Tanh graph with ±

Hi MATLAB Community,

How do I add ± to a,b,c,d like ing the graph?

Any help would be appriciated.

a = 95.80266;
b = -88.53938; 
c = 30.84839; 
d = -16.56475;  

y = a+b*tanh((x+c)/d);
 
plot(y,tanh(x)); 
grid on;

Answer 1

[Star Strider]

That is an annotation textbox, specifically the result of Create Text Box Annotation with Multiline Text in MATLAB.

You can try usiing them, however I have always found them extremely difficult to work with, so I use text objects instead, since they are simply easier to work with.

[Kenneth Bisgaard Cristensen]

Hi Thanks,

What I'm looking for, is hoe to create a = 95.80266 ±2.70049, so I can plot a curve matching the one in the picture.

[Star Strider]

My pleasure!

Try this:

a = 95.80266;
b = -88.53938; 
c = 30.84839; 
d = -16.56475;  

x = linspace(-200, 120, 500);
y = a+b*tanh((x+c)/d);

figure
plot(x, y)
xlabel('Temperature [°C]')
ylabel('Absorved Energy [J]')

The ± values are likely confidence intervals on the parameters. It iwould be difficutl to incorporate them into the plot.

Note — The is a statistic on the goodness-of-fit of the curve to the data. It has nothing to do with ‘x’.

[Kenneth Bisgaard Cristensen]

Okay thanks, that was really helpful, I appriciate it.

[Star Strider]

As always, my pleasure!