# Graphic of 2π periodic function

**URL:** <https://scilab.discourse.group/t/graphic-of-2-periodic-function/268>\
**Category:** General usage\
**Created:** [November 28, 2023, 5:51pm UTC](https://scilab.discourse.group/t/graphic-of-2-periodic-function/268 "2023-11-28T17:51:45Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Abdelkader](https://avatars.discourse-cdn.com/v4/letter/a/bbce88/32.png) [@Abdelkader](https://scilab.discourse.group/u/Abdelkader)\
**Post date:** [November 28, 2023, 5:51pm UTC](https://scilab.discourse.group/t/graphic-of-2-periodic-function/268/1 "2023-11-28T17:51:45Z")

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Can someone tell me please how do I plot 2D graphic of 2\pi periodic function y = x^2-\pi^2 with range of x = -\pi to x = \pi ? Thank you

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<div class="post-metadata">

**Author:** ![onkanat](https://yyz2.discourse-cdn.com/free1/user_avatar/scilab.discourse.group/onkanat/32/269_2.png) [@onkanat](https://scilab.discourse.group/u/onkanat)\
**Post date:** [November 28, 2023, 6:51pm UTC](https://scilab.discourse.group/t/graphic-of-2-periodic-function/268/2 "2023-11-28T18:51:16Z")

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```auto
x = linspace(-%pi,%pi,64);
y = x.^2-%pi.^2;
plot(x,y);

```

And this [Plot 2D Graphic Beginner Question](https://scilab.discourse.group/t/plot-2d-graphic-beginner-question/259)

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<div class="post-metadata">

**Author:** ![mottelet](https://yyz2.discourse-cdn.com/free1/user_avatar/scilab.discourse.group/mottelet/32/13_2.png) [@mottelet](https://scilab.discourse.group/u/mottelet)\
**Post date:** [November 29, 2023, 3:24pm UTC](https://scilab.discourse.group/t/graphic-of-2-periodic-function/268/3 "2023-11-29T15:24:42Z")

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Hello, if you want to plot this periodic function outside the principal range of x, you have to use `pmodulo` to compute the principal determination of each x, like this:

```scilab
x = linspace(-10,10,1000);
xp = pmodulo(x+%pi,2*%pi)-%pi;
plot(x,xp.^2-%pi^2)

```

 ![Screenshot 2023-11-29 at 16.25.56](https://global.discourse-cdn.com/free1/uploads/utc/original/1X/a73a29601bf4460e3a046a453bf80b3c66909641.png)