CODEWITHSUNDEEP
matlabrowaddition
ealeon
ealeon

Reputation: 12452

Adding a row to a matrix

I have a matrix 2x20 from a text file
I want to add a row of ones to that matrix

twopts = reshape(textread('input.txt', '%s'),2,20); % 2 by 20
ones_row = ones(1,20);   %1 by 20 of ones

twopts = [twopts;ones_row]

Gives me an error:

"Error using vertcat CAT arguments dimensions are not consistent."

But the matrix dimensions match... 2x20 and 1x20 to make 3x20

What's wrong with it and how do I fix it?

Upvotes: 2

Views: 427

Answers (3)

Swagatika
Swagatika

Reputation: 885

In case your data is numerical, you may try using

twopts = importdata('input.txt');

ones_row = ones(1,20);

twopts = [twopts; ones_row];

Upvotes: 0

angainor
angainor

Reputation: 11810

Instead of reading strings, as you do now, try to simply read numbers (that is - if your data is numbers). Simply omit the %s parameter to textread:

twopts = textread('input.txt');
ones_row = ones(1,20);
twopts = [twopts; ones_row];

Upvotes: 0

Junuxx
Junuxx

Reputation: 14251

twopts is a cell array of strings and ones_row is a matrix, you can't put these together.

Does this do what you want?

twopts = reshape(textread('input.txt', '%s'),2,20); % 2 by 20
ones_row = ones(1,20);   %1 by 20 of ones
ones_row = mat2cell(ones_row, 1, ones_row); % convert to cell array

twopts = [twopts;ones_row]

Alternatively, if the input data contains numbers, not text, you might want to convert the cell array to a matrix instead:

twopts = reshape(textread('input.txt', '%s'),2,20); % 2 by 20
twopts = cellfun(@str2num,twopts);
ones_row = ones(1,20);   %1 by 20 of ones

twopts = [twopts;ones_row]

Upvotes: 2

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