MATLAB App Designer: How to display a scatter plot on the UIaxes with linear fit and equation of line ?

I am migrating my script to App Designer.

Below script (normal script) is ploting a scatter plot with displayed linear fit and equation of line (figure 1).

Normal script:

str = [107.0176,  256.7374,  257.2012,  441.7806,  420.5170,  602.7027,  591.8610,  756.6289,  896.9324];
Ec1 = [23.8829,   19.0262,   28.8904,   22.3871,   29.4871,   24.5282,   29.3028,   26.3303,   24.5477];

createfigure(str,Ec1)

Figure 1:

Above script cannot be written as such when I am migrating to App Designer. Thus I did rewrite the script (App designer script) to get the best possible same outcome but only able to generate as in figure 2. The generated figure has no equation of line displayed and the linear fit need long script for it to be plotted.

App designer script:

str = [107.0176,  256.7374,  257.2012,  441.7806,  420.5170,  602.7027,  591.8610,  756.6289,  896.9324];
Ec1 = [23.8829,   19.0262,   28.8904,   22.3871,   29.4871,   24.5282,   29.3028,   26.3303,   24.5477];

p = polyfit(str,Ec1,1);
f = polyval(p,str);
plot(app.UIAxes3,str,Ec1,'o',str,f,'-')
hold (app.UIAxes3,'on')
legend(app.UIAxes3,'show')
hold (app.UIAxes3,'off')

Figure 2:

Seek your kind help on this very issue.

disclaimer: this script is the simplified version of full script.

Answer 1

[VBBV]

str = [107.0176,  256.7374,  257.2012,  441.7806,  420.5170,  602.7027,  591.8610,  756.6289,  896.9324];
Ec1 = [23.8829,   19.0262,   28.8904,   22.3871,   29.4871,   24.5282,   29.3028,   26.3303,   24.5477];

p = polyfit(str,Ec1,1);
f = polyval(p,str)

f = 1×9

24.4321 24.8096 24.8108 25.2763 25.2227 25.6821 25.6548 26.0703 26.4241

str1 = linspace(min(str),max(str),9)

str1 = 1×9

107.0176 205.7570 304.4963 403.2357 501.9750 600.7143 699.4537 798.1930 896.9324

plot(str,Ec1,'o',str1,f,'-')

[VBBV]

change for x-vector when plotting using values obtained from polyval

[AIZAT AKMAL BIN A.MOHAMAD BEDDELEE]

Hi VBBV,

x-vector is not my main concern but I am more keen to have the equation of line for the linear fit to be displayed on the UI axes on MATLAB APP DESIGNER.

Thus, I believe your proposal is unacceptable answer for this issue.

Thanks.

[VBBV]

str = [107.0176,  256.7374,  257.2012,  441.7806,  420.5170,  602.7027,  591.8610,  756.6289,  896.9324];
Ec1 = [23.8829,   19.0262,   28.8904,   22.3871,   29.4871,   24.5282,   29.3028,   26.3303,   24.5477];

p = polyfit(str,Ec1,1);
f = polyval(p,str);
str1 = linspace(min(str),max(str),9);
y = (vpa(poly2sym([p]),3))

y = 

[VBBV]

To find equation, use poly2sym and to display equation in the plot use annotation or text functions using the axes handles

[VBBV]

str = [107.0176,  256.7374,  257.2012,  441.7806,  420.5170,  602.7027,  591.8610,  756.6289,  896.9324];
Ec1 = [23.8829,   19.0262,   28.8904,   22.3871,   29.4871,   24.5282,   29.3028,   26.3303,   24.5477];

p = polyfit(str,Ec1,1);
f = polyval(p,str);
str1 = linspace(min(str),max(str),9);
y = (vpa(poly2sym([p]),3))

y = 

plot(str,Ec1,'o',str1,f,'-')
ax = gca

ax = 
  Axes with properties:

             XLim: [100 900]
             YLim: [18 30]
           XScale: 'linear'
           YScale: 'linear'
    GridLineStyle: '-'
         Position: [0.1300 0.1100 0.7750 0.8150]
            Units: 'normalized'

  Show all properties

text(ax,300,26,sprintf('y = %.5fx + %.2f',p(1),p(2)))