adding only to the y value in matrix

I need to add a constant only to the y value of all inputs in a matrix.

The task is to make it look like its lifted upwards on a graph.

[Geoff Hayes]

Paul - which row or column of the matrix corresponds to the y value? Whichever that might be, just add the constant to it.

constantValue = 42;
matrix = randi(255,10,2);
matrix(:,2) = matrix(:,2) + constantValue; % add the constant value to the second column

[Paul Jackson]

It seems like i misunderstood the task. It seems like I need to create a matrix that has 0 for every x value and the value i want to add for every y value. I then need to add that matrix to the original one

[Geoff Hayes]

Or just add a constant to the column (or row) of the matrix that has the y data. You may need to show us what your current matrix looks like (how is it constructed, where are the x and y values), etc.

Answer 1

[Steven Lord]

The answer depends on how you're storing your coordinate data. Is it stored as two columns, the first x and the second y?

v = (1:10).';
xy = [v, v.^2];
plot(xy(:, 1), xy(:, 2))

If so just add your constant to the second column of xy.

Is your data stored as arrays of points each containing x, y, and z data?

[x, y, z] = peaks;
surf(x, y, z)

If so add your constant to the y array.

Is your data stored as an image?

im = imread('ngc6543a.jpg');
imshow(im)

In this case you'll probably want to add the 'XData' and 'YData' options to your imshow call.

Or is it stored in some other way? If so please describe how you're storing your data.