JSFiddle here : CLICK. For example, in the case of an ease-in-out timing. The first parameter specifies the number of intervals in the function. -webkit-animation-timing-function: steps(1,end); animation-timing-function: steps(1,end); See this jsFiddle. 7 The. <step-easing-function> Specifies a steps() function that divides the animation into a set number of equal-length intervals or "steps", causing the animation. Timing Functions. And draw can go beyond properties, create new elements for like fireworks animation or something. Put all your images in one sprite by creating a line of frames that preserves the images’ order, i. Creating a Pulse Loader with Tailwind CSS: A Step-by-Step Guide. An animation timing function defined within a keyframe block applies to that keyframe. However, you can also set custom styles for it according to your. . We include two <time> values. I want to be able to change animation-timing-function and -webkit-animation-timing-function etc. In between each stop the interpolation is done in a linear way, explaining the name of the function. Or you can make transition very quick using very steep bézier curve, such as cubic-bezier(. CSS Animations Level 1 <easing-function> # <animation-name> 설정 수에 따라 하나 이상의 <easing-function>을 콤마로 구분해서 작성할 수 있다. آموزش ویژگی animation-timing-function در CSS. Click on the RERUN button in the above demo to see the animation. animation-timing-function: steps(3, end) Values ease Default. The above curve defines how the output (y. 1. Like other CSS animations, we can use any supported timing function here, but we need to apply the same function for all animations (move1, move2, and move3) at the same time. For example, if n is 2 then it will divide the animation into 2 parts. 4-CSS Animation. The animation-timing-function can work with any of the easing functions, as well as three other timing functions: step-end, step-start, and steps. The animation is created by gradually changing from one set of CSS styles to another. Use JavaScript to set the text for the inner element and set the --characters variable containing the character. It basically tell CSS to render the element at its initial state until the time runs out, and then immediately render the end state. e. The animation-timing-function specifies the speed curve of an animation. steps()函数的第二个参数. css. Hover me. Pre- and post-animation state: animation-fill-mode, step 3. 5. typewriter ” selector. For keyframed animations, the timing function applies between keyframes rather than over the entire animation. The animation CSS property is a shorthand property for the various animation properties: animation-name, animation-duration, animation-timing-function, animation-delay, animation-iteration-count, animation-direction, animation-fill-mode, and animation-play-state. In this animation, we're using a linear timing function. Now, you can easily fine-tune your style for the color schemes. You are free to choose the length. animation-timing-function is never used in Method 2 and Method 3. animation-timing-function使用了三次贝塞尔（Cubic Bezier）函数生成速度曲线，可以让我们的动画产生平滑的过渡。. In the transition shorthand, the first <time> value is the transition-duration. Let's define each below. If no animation-timing-function is specified on a keyframe, the corresponding value of animation-timing-function from the element to which the animation is applied is used for that keyframe. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. The steps () method is a timing function in animation property that divides an animation into n steps, displaying each step at equal intervals of time. cabin rule to cabins 10s linear infinite. <easing-function> Each <easing-function> represents the easing function to link to the corresponding property to transition, as defined in transition-property. Not sure where the problem is. Pre- and post-animation state: animation-fill-mode, step 4. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. You may specify multiple easing functions; each one will be applied to the corresponding property as specified by. キーフレームに animation-timing-function が指定されていない場合、そのキーフレームにはアニメーションが適用された要素から animation-timing-function の適切な値が. <easing-function> The easing function that corresponds to a given animation, as determined by animation-name. In a CSS animation, you can specify your timing function as part of the shorthand animation property, or by setting the animation-timing-function property directly. Moreover, the CSS step() function will break the animation into segments; in this case, it’s the text that will be broken into segments. Link to. For more details, you can read in my blog which shows you more on the math and physics behind. 2. The CSS animation-timing-function defines the pace of your. タイミング関数は @keyframes ルール内にあるそれぞれのキーフレームに指定されることがあります。. In the above example, we’re using a linear timing function, which means that the box is constantly moving at the same speed. Steps. 0) curve which results in a constant speed of the animation throughout its entire cycle. animation-direction: sets the direction of the animation after the cycle. Ideally I'm looking for something that will work with dynamically changing text of various lengths. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. A more natural approach would be to accelerate, maintain speed, and then "brake": I have a div where I'm animating the width from 0 to 100% in 3 steps. It must be a. Cú Pháp: animation-timing-function: value; Xem Demo. */ steps(2, start) /* The second parameter is optional. The animation-timing-function property can have the following values: ease - Specifies an animation with a slow start, then fast, then end slowly (this is default) linear - Specifies. For example, you can use the transition-duration class to specify the length of the transition, or the transition-timing-function class to specify an easing function that controls the acceleration of the transition. With @keyframes, you can define how an element should look at various points during an animation. Using the step-end Keyword. There are also cases where the animated elements can be made to start off moving in the wrong direction. I'm trying to get the animation to scale up and down in a bouncy way using the animation timing function. See the Pen css animation keyframe by Totori () on CodePen. These timing functions are valid : /* There is 5 treads, the last one happens right before the end of the animation. The animation-timing-function property in CSS is used to specify how the animation makes transitions through keyframes. animation. Configuring an animation. It appears as if the element bounces off the left side. The ‘animation-timing-function’ in CSS determines how fast your animation will play: animation-timing-function: value; To make the changes smoother, a speed curve is used. We don't get a single ease for the entire animation. So, add the following code: /* Make CSS animation smooth */. Sorted by: 1. alternate. From here, I'm going to use the Step timing function. The CSS for Typing Animation. In animation, we defined the animation in the shorthand method, in only one line, but we could also write it using 4 lines, in the long form:. ) each represent cubic Bézier curve with fixed four point values, with the cubic-bezier() function value allowing for a non-predefined value. Enter animation-timing-function. animation-duration: value; Note: if you don't define the duration for the animation, it will not run at all, as the default value is 0s. CSS свойство animation-timing-function CSS свойства Определение и применение. The only change between this and the first example is that we've used different transition timing functions. 5s的淡入动画。. These timing functions are valid : /* There is 5 treads, the last one happens right before the end of the animation. The non-step keyword values (ease, linear, ease-in-out, etc. Step 3: Define other animation properties you need. animation-timing-function: step-end; The animation stays at the initial state until the end, when it instantly jumps to the final state. As the name implies, this enables you to set a delay between when the transition is triggered, and when the animation actually begins. It is a shorthand for animation-name, animation-duration, animation-timing-function, animation-delay, animation-iteration-count, animation-direction, animation-fill-mode, animation-play-state, and animation-timeline. CSS Animation. Customizing your theme. The final transition property is CSS transition-delay. */ steps(2) These timing function are invalid : This function accepts a number of stops, separated by commas. item. The animation has the same speed from start to end: ease: Default value. shewine August. <timing-function> Chaque valeur <easing-function> représente une fonction temporelle à rattacher à une animation définie grâce à animation-name. Within a keyframe, animation-timing-function is an at-rule-specific descriptor, not the property of the same name. An easy fix is to simply change the timing function to ease. If no animation-timing-function is specified on a keyframe, the corresponding value of animation-timing-function from the element to which the animation is applied is used for that keyframe. Within a keyframe, animation-timing-function is an at-rule. The animation CSS property is a shorthand property for the various animation properties: animation-name, animation-duration, animation-timing-function, animation-delay, animation-iteration-count, animation-direction, animation-fill-mode, and animation-play-state. Both the values steps(4,start) and steps(4,end) specify that there are 4 steps. These functions describe the transition. Here is a snippet of what the shorthand and longhand variants might look like: /* shorthand */ #foo { animation: bobble 2s ease-in infinite. ) each represent cubic Bézier curve with fixed four point values, with the cubic-bezier() function value allowing for a non-predefined value. I will be demonstrating any more examples of using steps() in articles to come. Easing functions may be specified on individual keyframes in a @keyframes rule. as per your fiddle, there are definitely three stages to the animation, but it's just getting darker and darker. Note : When you specify multiple comma-separated values on an. Saved searches Use saved searches to filter your results more quicklyanimation は CSS の一括指定プロパティで、スタイルの間のアニメーションを適用します。これは animation-name, animation-duration, animation-timing-function, animation-delay, animation-iteration-count, animation-direction, animation-fill-mode, animation-play-state の一括指定です。こちらはCSSアニメーションのイージングプロパティ（animation-timing-function）で指定可能な値と、比較用の動作サンプル集になります。. The following code will make the transition stay on the last frame: -webkit-timing-function:ease; -webkit-iteration-count:1; This is wrong, it's forwards, not the iteration count. The first parameter specifies the number of intervals in the function. ease is the animation-timing-function property'sMaster uses the selector html. animation-timing-functionの設定方法. Resumen. Description. wheel selector, you created four different properties to control the animation. ,fn) with a custom timing function. 85,. This can be specified in either in seconds or in milliseconds. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. Create a reference variable of Animated. Syntax:An animation (let's say w/ 4 steps) when set to ease it will always ease every step of the animation. will be familiar with keyframes. animation-timing-function: steps(30, end) makes the animation play in a stepwise manner, instead of smoothly. This lets you vary the animation's speed over the course of its duration. Stopping and starting an animation: animation-play-state. In other words, the timing function is applied at the start of the keyframe and at the end of the keyframe. The state of the element will not vary gradually, but rather jump from state to state in separate instants. The animation shorthand CSS property applies an animation between styles. With your . Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself. By default, the animation-timing-function is set to ease if not specified by the developer. CSS свойство animation-timing-function определяет кривую скорости для анимации (используется математическая функция - кубическая кривая Безье). exports = { theme: { extend: { animation: { sideways: "sideways 3s linear infinite", }, }, }, }; Configure your @keyframes value. 1 Timing functions for keyframes; 3. Using this timing function, the animation jumps immediately to the. easing: Easing function to define curve. I'm using keyframes and an animation-timing-function of steps (3). I have an animation in CSS that spins an image around its centre. . Modified 8 years, 2 months ago. A mixture of both slow and fast timing within a scene gives texture and interest to the movement. animation. If multiple keyframe sets exist for a given name, the last one encountered by the parser is used. config. The following types of timelines can be set via. 2. The animation has a slow start, then fast, before it ends slowly. Pre- and post-animation state: animation-fill-mode, step. programmatically in JavaScript. 1 I have a div where I'm animating the width from 0 to 100% in 3 steps. css. 5 seconds. steps() is a timing function that allows us to break an animation or transition into segments, rather than one continuous transition from one state to. A value of steps(1,start) means that the animation has only one step and it happens right at the start of the animation itself. ease-out. Animation is all about the timing. That is, you can specify a timing function using the easing property. 0, 1. Read about initial: inherit: Inherits this property from its parent element. The syntax of steps is as follows: animation-timing-function: steps (steps_number, direction); It’s all very simple: the number of steps is an integer. Share. As you might already know, the linear timing function can be easily set in CSS by using the linear. La lista de propiedades CSS que pueden ser animadas está disponible; cabe señalar que estas son las mismas. The steps() timing function is unique to CSS and can be used to create some interesting effects. <easing-function> The easing function that corresponds to a given animation, as determined by animation-name. In This Article. ” The box starts slowly, accelerates in the middle, and then decelerates towards the end. Result: CSS Code: #myDIV { animation-timing-function: ease-in-out; } Click the property values above to see the result. ease: animation-timing-function: ease; Chuyển động ban đầu sẽ chậm, sau đó nhanh, đến lúc kết thúc sẽ từ từ, đây là dạng mặc định. About External Resources. ttf-ease-in, etc. ease-in-out - starts slowly and ends slowly. transition-timing-function: ease; transition-timing-function: linear; transition-timing-function: step-end; transition-timing-function: steps(4, end); I hope in the future we get more. animation-timing-function : xác định tốc độ chuyển động của một animation sẽ như thế nào. Arguably the most fundamental of the 12 principles of animation. ease-in: animation. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. About External Resources. Within a keyframe, animation-timing-function is an at-rule-specific. animation. For an example, in none shorthand writing :. For example, although mathematically we might expect that a step timing function with a step position of jump-start would step up (i. Steps. The animation-range-start CSS property is used to set the start of an animation's attachment range along its timeline, i. Animation Timing. See animation iteration count for more examples. Suppose we want to add a utility class that moves sideways; we proceed like this: module. Browser support tables for modern web technologies. ). We have the following timing functions. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. لطفا در ادامه با آموزش ویژگی animation-timing-function در CSS با من همراه باشید. Syntax: animation-timing-function: linear | ease | ease-in | ease-out | ease-in-out |step-start | step-end| steps(int, start | end) | cubic-bezier. The animation-timing-function property. Please refer to the CSS transition function to know more. The animation-timing-function sets the animation speed curve. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. To apply it to the whole animation you can use:These timing functions are valid : /* There is 5 treads, the last one happens right before the end of the animation. There are different techniques provided by this library to animate your component’s properties, the most basic being `Animated. Add animation with the animation property. animation-timing-function: step-end; The animation stays at the initial state until the end, when it instantly jumps to the final state. The typewriter effect relies on the CSS step() timing function and animation-fill-mode: forwards. animation-name 의 초기 값은 none 입니다. ) each represent cubic Bézier curve with fixed four point values, with the cubic-bezier() function value allowing for a non-predefined value. That will be a blinking cursor at the end of the text. ease-in - starts slowly, but accelerates. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. . Easing functions are serialized using the common serialization patterns defined in with the following additional requirements:. A more natural approach would be to accelerate, maintain speed, and then "brake":Step 3: Add the Magic. I copied “cabins 10s linear infinite” and pasted it after the animation property in the cabin selector. transition-timing-function: steps (4, end); By using steps () with an integer, you can define a specific number of steps before reaching the end. Read about inheritThe transition-timing-function CSS property is used to describe how the intermediate values of the CSS properties being affected by a transition effect are calculated. You can use steps as your timing-function to pause the animation until the next keyframe. CSS, Animation · May 24, 2021. Note that some of the easing functions listed there cannot be written in CSS. The animation-timing-function property specifies the speed curve of the animation. Within a keyframe, animation-timing-function is an at-rule-specific. The first parameter specifies the number of intervals in the function. Linear Functions. Here is the jsfiddle:. animation-timing-function 除了上面的几种常用方式之外，还有个一实用的函数，steps(number_of_steps, direction)，这个函数叫做阶梯函数. Link to Codepen Example. In the world of web development, user experience is king. Squash and stretch is applied to give a sense of weight and/or flexibility to objects or even to people. At the core of the Web Animations timing model is the process that takes a local time value and converts it to an iteration progress. By default, Tailwind provides utilities for four different example animations, as well as the animate-none utility. 1,. We’ve covered linear functions in one of the previous examples, so let’s do a quick recap. animation-timing-function: linear; OR, if you are using the animation shorthand property, you can also specify the. The non-step keyword values (ease, linear, ease-in-out, etc. The points P 0 and P 3, which represent the start and end of the animation cycle, are always set to (0,0) and (1,1) repectively. 5s; Now we’ve created our fly cycle, our bird is currently flapping her wings but isn’t going anywhere. Animation in your slide deck is a great way to add visual interest. 0), the default value, increases in velocity towards the middle of the animation, slowing back down at the end. Saved searches Use saved searches to filter your results more quickly こちらはCSSアニメーションのイージングプロパティ（animation-timing-function）で指定可能な値と、比較用の動作サンプル集になります。. Easing functions may be specified on individual keyframes in a @keyframes rule. animation-timing-function: steps(n, jump-none); Here [easing] is one of those listed at easings. It could maybe be done with a pseudo-element where you animate the content attribute, but support of CSS animations on pseudo-elements is still somewhat sketchy. */ steps(2, start) /* The second parameter is optional. The timing function is not limited by Bezier curves. An animation timing function defined within a keyframe block applies to that keyframe. Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself. animation-delay : xác định độ trễ của mỗi lượt chuyển động. Los posibles valores son una o varias <timing-function> (en-US). It describes how an animation will progress over one cycle of its duration, allowing it to change speed during its course. I did the following code in SCSS (you can see in the pen above ). ease). CSS animations offers a lot of different parameters you can tweak: animation-name — the name of the animation which references an animation created using keyframes. By using steps () with an integer, you can define a specific number of steps before reaching the end. 30 is the number of steps the animation takes, and these steps are spread evenly until the end of the animation. animation. Every one second, the element will move 10px to the left and 10px down, until the end of the animation, and then again in reverse forever. The function takes two parameters — the first specifies the positive number of steps we want our animation to take. You may specify multiple easing functions; each one will be applied to the corresponding property as specified by. You can set a greatful parameters in animation, called animation-timing-function allowing you to set perfectly and mathematicaly the animation : With bezier curve values or, if, like me, you're not that good mathematician, a parameter call "step()". The animation begins and ends gradually; this value is equivalent to cubic-bezier(0. Viewed 331 times 0 I've been trying to blink two colors, using the following CSS rules but the colors just ends up blending. keyframes object, then add the animation to theme. */ steps(2, start) /* The second parameter is optional. Specify when the style change will happen in percent, or with the keywords "from" and "to", which is the same as 0%. animation-timing-function: steps(30, end) makes the animation play in a stepwise manner, instead of smoothly. The non-step keyword values (ease, linear, ease-in-out, etc. auto Experimental. This function accepts a number of stops, separated by commas. Negative values are invalid. The animation-composition property specifies the operation to perform to produce the final effect value after compositing the. If an animation has the same starting and ending properties, it’s useful to comma-separate the 0% and 100% values inside @keyframes: @keyframes pulse { 0%, 100% { background-color: yellow; } 50% { background-color:. Step 2: What is a sprite? The first that you should know is what kind of image you’re actually working with. The designers gave us an example written in HTML and CSS which uses cubic-bezier. See scroll() for more information. 2 Animations; 3 Keyframes. */ steps(5, end) /* A two-step staircase, the first one happening at the start of the animation. This can be specified in seconds or milliseconds. Animation form, animation-timing-function. There is. Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself. In CSS, we use the animation-timing-function property to apply easing to an element's animation. Let’s see more of them. We’ve covered linear functions in one of the previous examples, so let’s do a quick recap. loading { animation-name: rotate; animation-duration: 3s; animation-timing-function: linear; animation-iteration-count: infinite; } For a reference of what each property and value means:Then, set the animation-timing-function to define how the animation progresses. –La propriété animation-timing-function définit comment la vitesse de l'animation va changer pendant chaque cycle, et pas pandent l'animation entière. animation-duration: 1. Each stop is a single number that ranges from 0 to 1. We can adjust the speed curve of animation throughout the duration. The animation shorthand CSS property applies an animation between styles. The step timing functions divides the input time into a specified number of intervals that are equal in length. As you can see, the hand jumps to the 5-second. For example, in the case of an ease-in-out timing function, an animation will ease in at the start of the keyframe and ease out at the end of the keyframe. A timing function (animation-timing-function in CSS) lets you change the animation speed curve. Set the animation property of the . Sorted by: 2. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. I'm using keyframes and an animation-timing-function of steps(3). That means we use getBoundingClientRect () on the element that will serve as a proxy for the start state, and divide it with the value from the end state. animatedobject { -webkit-animation-timing-function: linear; } and your animation will look more more less good, if a little robotic. animation-name: Specifies the name of the keyframe you want to bind to the selector: animation-duration: Specifies how many seconds or milliseconds an animation takes to complete: animation-timing-function: Specifies the speed curve of the animation: animation-delay: Specifies a delay before the animation will start: animation-iteration. steps Timing FunctionIf you want to skip gradual transition completely, you can use animation-timing-function: step-end (or steps(1,end); but you have to move your "target" state to the "middle" keyframe). Note: When you specify multiple comma-separated values on an animation-* property. transition-timing-function: steps(4, start); transition-timing-function: steps(4, end); A value of start would run the animation at the beginning of each step, whereas a value of end would run the. The animation-timing-function property, when declared for the entire animation, allows you to define how an animation progresses over a single iteration of the animation. step-start: Equivalent to steps(1, start) step-end: Equivalent to steps(1, end) steps(int,start|end) Specifies a stepping function, with two parameters. 2. The ease-in-out timing function creates a smooth and balanced animation, with both a gradual start and a gentle finish. Resumen. どのプロパティにアニメーションを適用するか指定する (all/none/プロパティ名) transition-duration. 9, 0. CSSを学び始めた方へ; animationプロパティについて学びたい方へ; 今回はanimation-timing-functionでアニメーションの変化についての解説になります。; 今回は、animationに関する記事になります。 animation-timing-functionとは、アニメーションの変化(速度)のスタイルを指定します。Launching a factory, step 2. The animation-timing-function property determines the pace of an. Its speed gradually increases because of gravity until it hits the ground. extend. The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. The <timing-function> CSS data type denotes a mathematical function that describes how fast one-dimensional values change during transitions or animations. こんな方に読んでほしい. Default value is 0, which means that no animation will occur: Play it » initial: Sets this property to its default value. It should be something like this:Timing Functions in CSS Animations. 1 Like. animation-timing-function: steps(4, end); By using steps() with an integer, you can define a specific number of steps before reaching the end. With the linear timing function, the animation is going. . If there are fewer timing functions. The values for animation-timing-function are ease, linear, ease-out, step-start and many more, as outlined in the spec. Using this timing function, the animation or transition stays in its initial state until the end, where it directly jumps to its final position. Animation-timing-function, step 2. hubspot. It is the way actions. animation-timing-function: linear: animation-timing-function: linear; Chuyển động sẽ cùng tốc độ từ lúc bắt đầu tới lúc kết thúc. Source. React Native Animation is an interesting topic where a dull application could be converted into an interactive and beautiful app. If no animation-timing-function is specified on a keyframe, the corresponding value of animation-timing-function from the element to which the animation is applied is used for that keyframe. js file and add your custom animation. The animation will repeat forever. But multi-step-spin breaks it into 4 distinct steps, and each step has the timing function applied:The animation-timing-function CSS property sets how an animation progresses through the duration of each cycle. The transition has a *constant speed. If no animation-timing-function is specified on a keyframe, the corresponding value of animation-timing-function from the element to which the animation is applied is used for that keyframe. 1 Answer. animation-timing-function: steps(4, end); By using steps() with an integer , you can define a specific number of steps before reaching the end. 1 Introduction. If a given animation time offset is duplicated, all keyframes in the @keyframes rule for that percentage are used for that frame. " Use the wave animation" you need to be using the animation name “wave”" have a linear timing function" you need to be using linear. The keyword values ease, linear, ease-in, ease-out, and ease-in-out are serialized as-is, that is, they are not converted to the equivalent cubic. 目次. There is a CSS rule available for us to create animations called keyframes, defined in CSS as @keyframes. Animation steps are performed backwards, and easing functions are also reversed. The non-step keyword values (ease, linear, ease-in-out, etc. you can apply an animation-timing-function that adds personality to. 30 is the number of steps the animation takes, and these steps are spread evenly until the end of the. In this video, learn how to use the steps() timing function to create a sprite animation with CSS. I'm familiarizing myself with CSS animation, and have been attempting to switch content in/out with a fade transition. 5. You use it like this: transition-delay: 1 s ; Code language: CSS (css) To combine it with every else in transition, you just add the delay to the end:Easing functions may be specified on individual keyframes in a @keyframes rule. animation-timing-function: ease-in, linear; Each timing function is applied to the corresponding animation as specified by the animation-name property. Multiple steps. For a keyframed animation, the animation-timing-function applies between keyframes, not over the entire animation. If you omit a timing function from the call, the method uses the default timing function. If no timing function is specified for. Pre- and post-animation state: animation-fill-mode, step 5. In some cases, this is desirable; however, in the real world, motion usually doesn’t work like that. A @keyframes rule specifies the style. @keyframes rules don't cascade, so animations never derive keyframes from more than one rule set. 複数. Define two animations, typing to animate the characters and blink to animate the caret. ease-in - L'animation a un début lent, mais accélère à. سلام خدمت تمامی دوستان و همراهان محترم سایت آموزشی فری لرن ، امیدوارم که حال همگیتون خوب باشه. The steps () functional notation defines a step function dividing the domain of output values in equidistant steps.