Plotting figure with intp2

I have a coding to plot a figure and this is my coding:

[Xq_cond,Yq_cond] = meshgrid(linspace(min(Mwgrid),max(Mwgrid),length(amaxgrid)),linspace(min(amaxgrid),max(amaxgrid),n)); %import

Vq_cond = interp2(Mwgrid, amaxgrid, PL,Xq_cond,Yq_cond,'cubic');

where

Mwgrid = linspace(4.75,8.25,8); %linspace(4.8,7.6,50);

amaxgrid = linspace(0.19,0.42,36);

grid = meshgrid(Mwgrid,amaxgrid);

I also attach the PL in the .txt format

Is there any one can help me to solve the problem of plotting using intp2?

I wish my plot has the same figure like in the attachment