Shade area between a curve and a vertical line and the x axis

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I have the following code:
clc
clear
close all
x = [0:.001:.2];
y = normpdf(x,.1,.02);
subplot(211)
plot(x,y,'linewidth',2);grid;box on;
hold on
YL = get(gca, 'ylim');
YR = YL(2) - YL(1);
YL = [YL(1) - 1000 * YR, YL(2) + 1000 * YR];
line([.14 .14], YL, 'YLimInclude', 'off', 'linewidth', 2, 'Color', ...
'black','LineStyle','-.');
I want to shade the area shown below:
  2 Comments
Emmanuel Sarpong
Emmanuel Sarpong on 25 Aug 2023
I have the code below. I want to color or patch the area between the curves and wavelength (x- axis) from 3 - 5 um. I am not sure how to properly define the y limit for the patch so the patch can touch the curves. Any form of help would be appreciated. Thank you.
clc;
close all;
c=3*10^8; % speed of light in vaccum
h=6.626*10.^-34; % Planck constant
k=1.38*10.^-23; % Boltzmann constant
T=[700 900]; % Temperatures in Kelvin
Lam=(0.0:0.01:50)*1e-6; % in meters
figure(1)
for i=1:2
A2(:,i)=(2*pi*h*c*c)./((Lam.^5).*(exp((h.*c)./(k.*T(i).*Lam))-1));
hold on
plot(Lam*1e6,A2(:,i)*1e-10,'r','linewidth',2)
x = [3 5]; % Define x For patch
y = [0.152 0.19]; % Define y For patch
patch([x fliplr(x)], [zeros(size(y)) fliplr(y)], 'b')
hold off
xlabel('\lambda (\mum)','fontsize',20)
ylabel('Spectral exitance (W/cm^2/\mum)','fontsize',20) %for I2
title('Blackbody Radiation','fontsize',24)
ax=gca;
ax.XRuler.Exponent=0;
xlim([0 20])
end

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Accepted Answer

Star Strider
Star Strider on 29 May 2020
Add these lines:
xa = linspace(0.14, 0.2, 25); % Define ‘x’ For ‘patch’
ya = normpdf(xa,.1,.02); % Define ‘y’ For ‘patch’
patch([xa fliplr(xa)], [zeros(size(ya)) fliplr(ya)], 'r')
so the compllete revised code is now:
x = [0:.001:.2];
y = normpdf(x,.1,.02);
subplot(211)
plot(x,y,'linewidth',2);grid;box on;
hold on
YL = get(gca, 'ylim');
YR = YL(2) - YL(1);
YL = [YL(1) - 1000 * YR, YL(2) + 1000 * YR];
line([.14 .14], YL, 'YLimInclude', 'off', 'linewidth', 2, 'Color', ...
'black','LineStyle','-.');
xa = linspace(0.14, 0.2, 25); % Define ‘x’ For ‘patch’
ya = normpdf(xa,.1,.02); % Define ‘y’ For ‘patch’
patch([xa fliplr(xa)], [zeros(size(ya)) fliplr(ya)], 'r')
hold off
That should do what you want.

More Answers (1)

Image Analyst
Image Analyst on 29 May 2020
  2 Comments
Mohammad
Mohammad on 29 May 2020
I already checked that. That doesn't address my question. I want to shade area between 3 special curves.
Image Analyst
Image Analyst on 29 May 2020
Actually it did. You accepted Star's answer and you'll notice he used patch(), just like the FAQ did. You just needed to figure out the boundaries of the patch, which he kindly did for you.

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