MATLAB: Common x-axis from different stepped x-axis, new interpolated y-values based on new x-axis

Question

I have generated a simple example with 3 different x-axis. As you can see that each x1,x2 and x3 are stepped differently, starting and ending points are different. My goal is to have a common x-axis from all the three x1,x2 and x3. For which the starting is the minimum among the three and end point is max among all. The new x-axis should be equally stepped. For instance, x=[0,3,6,9,……..,36,39] and I need all the y1, y2 and y3 to be interpolated according to the new axis. It should not interpolate beyond its corresponding axis, by this I mean that for y2_new it shouldn't have values at x-axis 36 and 39 because x2 has max value of 34 (elaborated in the following example).

x1 = [0,2,3,7,10,12,17,21,22,39];

y1 = [110,112,113,117,110,122,121,131,156,129];

x2 = [2,7,11,13,17,23,25,34];

y2 = [100,120,129,152,131,128,129,110];

x3 = [1,5,10,14,18,22,29,31,35];

y3 = [80,120,129,142,171,148,119,135,101];

plot(x1,y1)

hold on

plot(x2,y2)

plot(x3,y3)

The final result should be like (length of x,y1_new, y2_new and y3_new is 14)

x = 0:3:39; % length is 14

and the new y's, all must have 14 values

y1_new = ……. contains 14 values

y2_new = [value, value, ……, NaN, NaN] this vector should also contain 14 values but last 2 are NaNs because the max of x2 is 34, no values beyond 34.

y3_new = ….

All these new values must be interpolated versions of y1, y2 and y3.

Answer 1

Solved it.

x_min= min([x1,x2,x3]);

x_max = max([x1,x2,x3]);

x=x_min:3:x_max;

y1_new = interp1(x1,y1,x);

y2_new = interp1(x2,y2,x);

y3_new = interp1(x3,y3,x);