plotting x and y differential

hello

I have plotted x and y data and seen evidence of a bifurcation. I want to plot x vs diff y.

this is what i did :

plot(nslogistic.x,diff(y))

this is what i got:

Error using plot

Data must be numeric, datetime, duration or an array convertible to double.

is it possible to plot x data and y differential?

gs

[Turlough Hughes]

The issue appears to be the class of the variables that you are inputting into the plot function. What is printed to screen when you enter nslogistic.x or diff(y) into the command line?

[Gavin Seddon]

Yes it appears I need to update the table with a V column then plot columns 1 and 3.

should i ask a new question or can someone tell me how to update the table with a diff y column?

GS

[Turlough Hughes]

I would start by saving your variables from the workspace as a .mat file and attaching the file to this question. The question is still about ultimately plotting the differential of y as a function of x so I don't think you need to ask another question. By a V column I assume you mean velocity?

[Gavin Seddon]

yes thank you. can you tell me how to print diff y into a third column (v) ? i will perform the work on the .mat file to save you doing it.

GS

[Turlough Hughes]

Please upload the .mat file containing the variables nslogistic and y.

Answer 1

[Raynier Suresh]

“diff(Y)” function calculates the difference between adjacent elements of Y along the first array dimension whose size is not equal 1. But to find the derivative of Y with respect to X you can use “diff(Y)/h” where h is the step size in X, if X doesn’t have equal step size then you can use diff(Y)./diff(X).

While using plot function make sure that the data type of the input arguments must be one of these type single, double, int8, int16, int32, int64, uint8, uint16, uint32, uint64, categorical, datetime, duration

Referring to the following links might be helpful:

Diff : https://in.mathworks.com/help/matlab/ref/diff.html

Plot : https://in.mathworks.com/help/matlab/ref/plot.html#bt17v9_-5