fplot showing different curve to plot

Hey there! I tried plotting a simple function using two ways:

1. By creating an anonymous function and using fplot() to produce the plot
2. By simply creating a normal function and using plot() to produce the plot

Here's the code for the first:

clear all
close all
clc

M = 100; 
p_b = 2; 

Q = @(p_a) M./(p_a + p_b);

figure(1)
fplot(Q, [0 35])
ylim([0 30])
xlim([0 25])

Here's the code for the second:

clear all 
close all
clc

M = 100; 
p_b = 2; 
p_a = [0:0.1:35];

Q = M./(p_a+p_b);

figure(2)
plot(Q,p_a)
ylim([0 30])
xlim([0 25])

The curves look identical but they're actually different if you use the data tips on the figures and compare them (see photo below)

Anyone know why this is? I'm a bit lost :(

Answer 1

[Torsten]

plot(p_a,Q)

instead of

plot(Q,p_a):

M = 100; 
p_b = 2; 

Q = @(p_a) M./(p_a + p_b);

hold on
fplot(Q, [0 35])
ylim([0 30])
xlim([0 25])
 
p_a = [0:0.1:35];
Q = M./(p_a+p_b);

plot(p_a,Q)
hold off
grid on

[PCR_7]

My god, 'twas such a simple fix... Thank you so much! So plot and fplot just have x & y the opposite way?

[Torsten]

plot(x-values,y-values)

https://de.mathworks.com/help/matlab/ref/plot.html

fplot(function handle or symbolic function of x,[minimum x-value maximum x-value])

https://de.mathworks.com/help/matlab/ref/fplot.html