Linear Transformation Contest: Sample Code in Matlab by dexterdev

steemstem · @dexterdev · Apr 3 '18 (edited)

$12.82

Linear Transformation Contest: Sample Code in Matlab

Here I will post my sample code corresponding to the running [contest on linear transformation](https://steemit.com/steemstem/@dexterdev/linear-transformations-a-20-sbd-coding-contest-announcement).

```
clear  %clear all variables from matlab memory workspace
close all % close all figure windows (like previous plots)
clc % clear the screen

%% This section just creates a square 2D mesh of vectors
[X Y] = meshgrid(-10:1:10); % coordinates for vector positions
VX = X; % X,Y components of vector
VY = Y;
quiver(X, Y, VX, VY, 2)
title('Input: The 2D space')
axis square

%% reshaping the vectors for linear transformation
YY=reshape(VY,[1 21*21]);
XX=reshape(VX,[1 21*21]);
XY=[XX ;YY];

A=[1 2;-0.5 1]; % Our transformation matrix A
XY_t=A*XY; % linear transform operation

%% This section just creates a "transformed" 2D mesh of vectors
X_t=reshape(XY_t(1,:),[21 21]);
Y_t=reshape(XY_t(2,:),[21 21]);
figure
quiver(X_t, Y_t, VX, VY, 2)
axis square
title('Output: The transformed 2D space')

```

***Don't use modified versions of this code as a solution! (A friendly warning.)***

The input and output of the code is given below:
### Input
<center>![](https://i.imgur.com/JpJyGWr.png)</center>


### Output
The transformation matrix considered is
***A=***
```
1      2
-0.5   1
```

<center>![o.png](https://steemitimages.com/DQmXjtTFdSQnr76QoFo8JDPjXnRrLqwyudFFx3vLgxgeSW3/o.png)</center>

## Yes I have copy-pasted my code from github!
Don't blame me for plagiarism because I have uploaded it yesterday in [github](https://raw.githubusercontent.com/dexterdev/STEEMIT/master/CONTESTS/linear_transformation.m). 

I am tagging #steemstem because this contest comes as a part of Linear algebra article I wrote recently. So I don't expect #steemstem vote for this. See those articles below:

- [Linear Transformations: A 20 SBD coding contest announcement!](https://steemit.com/steemstem/@dexterdev/linear-transformations-a-20-sbd-coding-contest-announcement)
- [Eigen Values and Eigen Vectors: Visually Explained!
](https://steemit.com/steemstem/@dexterdev/eigen-values-and-eigen-vectors-visually-explained)


---

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Join the active science community #steemSTEM at discord: https://discord.gg/BZXkmWw

#### And to steemSTEM beginners:
You can ask for help in our discord page. There are people ready to help you there.

<center>https://steemitimages.com/DQmPtnKZW6cQWBAzpA8yiqTDXSsVH9zEUyxFiek2kGEoA8g/bear.gif</center>
<center>gif courtesy: @rocking-dave</center>


---

**All images without image sources are my creations :)**


## <center>Follow me @dexterdev</center>

---

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`author`	dexterdev
`permlink`	linear-transformation-contest-sample-code-in-matlab
`category`	steemstem
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`created`	2018-04-03 14:24:51
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