How to do different scaling in x in maltab plot (multiple scales in X axis)?

Dear friends,

I have a "simple" plot question here, but I cant figure out. In my project, I need to give different scaling in x axis. Because the information in some ranges are not improtant. I made a simple example to demonstrate my question, hope it's clear enough.

Please check the pic I attached. Lets assume my "curve" is this Y = X, X= [0:1:90]. However, the Y information for given X = [A:1:B ] is not improtant, so I just want to SHRINK or make it smaller, so that other range X=[0:A] & [B:90] information will be enlarged and easier to read.

Lets say A=30, B =60, C = 90. (Actually, any number is fine, just trying to make an simple example.) Anyone can advise me how to do it ? thanks in advance.

I tried to do [A:10:B] , but after the plot, the position of A B dont change, so not working :(

Answer 1

[Ameer Hamza]

There is no built-in command to do such a thing in MATLAB. One of the workarounds is to create multiple axes objects and connect them seamlessly. Refer to my answer here: https://www.mathworks.com/matlabcentral/answers/601147-extending-specific-y-axis-values

[sun]

hey, buddy. thank you! I used your way, it's working.

[Ameer Hamza]

I am glad to be of help!

Answer 2

[Mathieu NOE]

hello

forget my first attempt (deleted)

here hopefully a better code.

% let's generate some data
X= [0:1:90];
Y = 2*X;

% A, B segment indexes 
indA = (1:31);  % take the first 30 values
indB = (61:91);  % take the last values

ind_shr = (max(indA):10:min(indB)); % shrinked portion of data

XA = X(indA);
YA = Y(indA);

XB = X(indB);
YB = Y(indB);

X_shr = X(ind_shr);
Y_shr = Y(ind_shr);

% plot vectors / indexes
X_shr_plot = X_shr(1)+(0:length(X_shr)-1);
XB_plot = X_shr_plot(end)+(0:length(XB)-1);

figure(1)
plot(XA,YA,'b',X_shr_plot,Y_shr,'--b',XB_plot,YB,'b');grid
x_vector_ticks = [XA X_shr(2:end-1) XB];  % remove for Xtick labels the first and last element of X_shr (they already appear in XA(end) and XB(1)

for ci = 1:length(x_vector_ticks)
    XtickLabel{ci}  = num2str(x_vector_ticks(ci));
end

xticks(0:length(x_vector_ticks)-1)
xticklabels(XtickLabel)
xlabel('X value')
ylabel('Y value')

[sun]

hey, friend. Thanks so much for your code and time! It's awesome.

I do saw your style ~ you played tricks on the side of algorithm, and it's truly working! However, there is only one downside, it's not that simple. Buddy, please check another answer here. I applied his way, it's very simple styple. What you do is, you plot 3 different scale, then put them together on one figure.

Thank you again!

[Mathieu NOE]

hello

yes, I recognize it's a bit trickky - but the other option does not work on my older matlab.

I'm used to do complicated stuff that is easier now with newer matlab