create a new column of data showing (n+1)-n of old column

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Joseph Tirado 2022-1-16

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评论： Joseph Tirado 2022-1-17

I need to find the amount each data point increases by for each point in a clumn of data. I want to create a new column that calcuates the next point subtracted by the point right before it. if the colmn was labeled "x" it would function something like this: x(n+1)-x(n). Can anyone help?

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Answer 1

Cris LaPierre 2022-1-16

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This is what the diff function does.

If X is a vector of length m, then Y = diff(X) returns a vector of length m-1. The elements of Y are the differences between adjacent elements of X.Y = [X(2)-X(1) X(3)-X(2) ... X(m)-X(m-1)]

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Joseph Tirado 2022-1-17

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Answer 2

Image Analyst 2022-1-16

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https://ww2.mathworks.cn/matlabcentral/answers/1630135-create-a-new-column-of-data-showing-n-1-n-of-old-column#answer_875615

编辑：Image Analyst 2022-1-16

在 MATLAB Online 中打开

Do you mean like using the diff() function?

m = randi(9, 5, 7)
m = 5×7
     1     6     6     9     2     4     1
     8     8     4     8     3     7     2
     3     6     7     1     7     7     6
     8     1     8     3     9     1     8
     5     3     8     1     2     7     9
dHoriz = diff(m, 1, 2)
dHoriz = 5×6
     5     0     3    -7     2    -3
     0    -4     4    -5     4    -5
     3     1    -6     6     0    -1
    -7     7    -5     6    -8     7
    -2     5    -7     1     5     2
dVert = diff(m, 1, 1)
dVert = 4×7
     7     2    -2    -1     1     3     1
    -5    -2     3    -7     4     0     4
     5    -5     1     2     2    -6     2
    -3     2     0    -2    -7     6     1