# How to extract the data (y-axis) for a given value ( x-value)?

4 views (last 30 days)
Sumit Saha on 3 May 2021
Commented: KSSV on 4 May 2021
In this IDA_Plot_CLUSTER_UPDATED.mat file, I'm able to plot the (Figure B) upto certain points. But I want to get the exact pattern of that part i.e. in each curve (figure B) after the end point it will be extended upto 0.08 in a constant pattern. In this same plot, I want to get the y-values of corresponding to certain value of x.
Note : Limit y-values
PGA_Scale = [0.1:0.1:5];
figure(21) % to plot figure B
for tt = 1:60
plot(MIDR(tt,:),PGA_EQ(tt,1)*PGA_Scale,'-*r','linewidth',0.5);hold on;
end
xlabel('Maximum Storey Drift Ratio (MSDR)')
ylabel('IM (PGA)')
title('Incremental Dynamic Analysis (IDAs)for GMSetAll')
set(gcf,'position',[ 146 378 858 779])
set(findall(gcf,'-property','Fontsize'),'Fontsize',12)
print('DT2100','-dpng','-r300');
Figure A
Figure B
Desire_Limit_Collapse = 0.01; % values to be calculated from the graph corresponding this Desire_Limit_Collapse
for ii= 1:60
IM_Collapse_find(ii)= interp1(MIDR(ii,:),PGA_EQ(ii,1)*PGA_Scale,Desire_Limit_Collapse);
end

KSSV on 4 May 2021
PGA_Scale = [0.1:0.1:5];
figure(1) % to plot figure B
% for tt = 1:60
% plot(MIDR(tt,:),PGA_EQ(tt,1)*PGA_Scale,'-*r','linewidth',0.5);hold on;
% end
plot(MIDR',PGA_EQ'.*PGA_Scale','-*r','linewidth',0.5);
xlabel('Maximum Storey Drift Ratio (MSDR)')
ylabel('IM (PGA)')
title('Incremental Dynamic Analysis (IDAs)for GMSetAll')
set(findall(gcf,'-property','Fontsize'),'Fontsize',12)
print('DT2100','-dpng','-r300');
% Extend the plot
figure(2)
xi = linspace(0,0.08,100) ;
for tt = 1:60
yi = interp1(MIDR(tt,:),PGA_EQ(tt,1)*PGA_Scale,xi,'nearest','extrap') ;
plot(xi,yi,'-*r','linewidth',0.5);hold on;
end
Sumit Saha on 4 May 2021
Edited: Sumit Saha on 4 May 2021
@KSSV I want to interpolate data from the extended plot Kindly help me. In figure A, the way it had been shown.
KSSV on 4 May 2021
For extended plot too use interp1 with extrapolation on. This already I have shown/ given in the answer.

### Categories

Find more on 2-D and 3-D Plots in Help Center and File Exchange

R2017b

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!