Since the ‘y’ values are monotonically decreasing, using interp1 is straightforward with the second vector, however there is no way to work with the categorical variables to interpolate them, so I just went with the indices instead.—
% the original categorical x data
xS=categorical(["CTR" "-12" "-11" "-10" "-9" "-8" "-7"]);
xS = reordercats(xS,{'CTR' '-12' '-11' '-10' '-9' '-8' '-7'});
%Numerical version of above, removing the CTR entry (re-added back later)
cd = [1e-12 1e-11 1e-10 1e-9 1e-8 1e-7];
xS2 = log10(cd);
%The two different y data sets for each x data above
yS = [1 0.9995 0.9978 0.9815 0.8571 0.5576 0.4465]*100;
yS2 = [0.9995 0.9978 0.9815 0.8571 0.5576 0.4465]*100;
xSint = interp1(yS(2:end),(-12:-7),50) % 'xS' Must Be Numeric
xS2int = interp1(yS2,xS2,50) % 'xS2' 'yS2=50' Intercept
fig = figure(2);
%Actual plots
plot(xS,yS, '-o','Color','[0, 0.4470, 0.7410]',...
'LineWidth',3.5,'MarkerSize',20,...
'MarkerFaceColor','[0, 0.4470, 0.7410]','MarkerEdgeColor','k',...
'Linewidth',3);
hold on
yline(50, 'r--','Linewidth',3.5);
% Second to calc Ic50 value - uses numeric data
plot(xS2,yS2, '-o','Color','[0, 0.4470, 0.7410]',...
'LineWidth',3.5,'MarkerSize',20,...
'MarkerFaceColor','[0, 0.4470, 0.7410]','MarkerEdgeColor','k',...
'Linewidth',3);
xlabel('Dose [logM]'), ylabel('% Control')
leg = legend({'Cell Number','IC_5_0'});
leg.LineWidth=2.5;
leg.FontSize=28;
leg.NumColumns=1;
leg.LineWidth=2;
% Other plot stuff
box on
ax = gca;
set(gca,'linewidth', 2.5,'fontsize',28,'fontname','Helectiva') % Sets the width of the axis lines, font size, font
set(gca,'TickDir','out')
x0 = 50;
y0 = 50;
width=800;
height=600;
set(gcf,'position',[x0,y0,width,height])
Create a numeric vector for the categorical arrays to work with them, if my approach is incorrect.
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