# How do you set the first column of a 4x4 matrix = a vector

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Vincent Ogonda on 13 Aug 2020
Commented: hosein Javan on 13 Aug 2020
Vector X [380 250 220 200]
Matrix C=
[1257 679 220 203 1567 155 234 432 2345 445 238 556] How do I set the first column of matrix C equal to x

#### 1 Comment

Rik on 13 Aug 2020
You will probably benefit from a tutorial to get started with Matlab. One of the free options is Onramp.

hosein Javan on 13 Aug 2020
Edited: hosein Javan on 13 Aug 2020
X = [380 250 220 200]
C=[1257 679 220 203
1567 155 234 432
2345 445 238 556];
C(1,:)=X; % set the first row of C equal to vector X
size of C = 3*4 , and size of X = 1*4. you can set the first row of C equal to X. if not, I assume it was:
X = [380; 250; 220; 200]
C=[1257 679 220
203 1567 155
234 432 2345
445 238 556];
C(:,1)=X; % set the first column of C equal to vector X

Vincent Ogonda on 13 Aug 2020
Just another quick question if you have a 4x10 matrix. How do you set a loop from 2nd column to last column. Thanks
Vincent Ogonda on 13 Aug 2020
X = [380; 250; 220; 200] C=[1257 679 220 203 1567 155 234 432 2345 445 238 556]; C(:,1)=X; % set the first column of C equal to vector X
It worked for the row and not the column. Error in simulation it shows
hosein Javan on 13 Aug 2020
please copy and paste the code to your matlab command window. you have mistakenly defined matrix "C" as a row-vector rather than a 4*3 matrix. if you want to define a matrix in one line of code, use semicolon";" to distinguish rows.
C=[1257 679 220; 203 1567 155; 234 432 2345; 445 238 556];