## When using the command prompt, anything in your path or working directory can be run either as a script, function or class (to define objects)
�[0;31mError: The input character is not valid in MATLAB statements or expressions.
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%myscript
%plot --format svg
When using the GUI, your command history is saved, but it is better to save your work either as a script or a function or combination of both
Creating a default graph script: setdefaults.m
set(0, 'defaultAxesFontSize', 16)
set(0,'defaultTextFontSize',14)
set(0,'defaultLineLineWidth',3)
set(0, 'defaultAxesFontSize', 16)
set(0,'defaultTextFontSize',14)
set(0,'defaultLineLineWidth',3)
t_linear=linspace(0,10,100);
plot(t_linear,t_linear.^2)
xlabel('time (s)')
ylabel('displacement (m)')
#EOL
Graphics can be produced with a number of functions
2-D plots, 3-D plots, contour plots, 3D contour plots ...
x=linspace(-1,1,21); y=linspace(-1,1,21);
[X,Y]=meshgrid(x,y);
Z=(X.*Y.^3-X.^3.*Y)
Z =
Columns 1 through 7
0 0.1710 0.2880 0.3570 0.3840 0.3750 0.3360
-0.1710 0 0.1224 0.2016 0.2430 0.2520 0.2340
-0.2880 -0.1224 0 0.0840 0.1344 0.1560 0.1536
-0.3570 -0.2016 -0.0840 0 0.0546 0.0840 0.0924
-0.3840 -0.2430 -0.1344 -0.0546 0 0.0330 0.0480
-0.3750 -0.2520 -0.1560 -0.0840 -0.0330 0 0.0180
-0.3360 -0.2340 -0.1536 -0.0924 -0.0480 -0.0180 0
-0.2730 -0.1944 -0.1320 -0.0840 -0.0486 -0.0240 -0.0084
-0.1920 -0.1386 -0.0960 -0.0630 -0.0384 -0.0210 -0.0096
-0.0990 -0.0720 -0.0504 -0.0336 -0.0210 -0.0120 -0.0060
0 0 0 0 0 0 0
0.0990 0.0720 0.0504 0.0336 0.0210 0.0120 0.0060
0.1920 0.1386 0.0960 0.0630 0.0384 0.0210 0.0096
0.2730 0.1944 0.1320 0.0840 0.0486 0.0240 0.0084
0.3360 0.2340 0.1536 0.0924 0.0480 0.0180 0.0000
0.3750 0.2520 0.1560 0.0840 0.0330 0 -0.0180
0.3840 0.2430 0.1344 0.0546 -0.0000 -0.0330 -0.0480
0.3570 0.2016 0.0840 0 -0.0546 -0.0840 -0.0924
0.2880 0.1224 0 -0.0840 -0.1344 -0.1560 -0.1536
0.1710 0.0000 -0.1224 -0.2016 -0.2430 -0.2520 -0.2340
0 -0.1710 -0.2880 -0.3570 -0.3840 -0.3750 -0.3360
Columns 8 through 14
0.2730 0.1920 0.0990 0 -0.0990 -0.1920 -0.2730
0.1944 0.1386 0.0720 0 -0.0720 -0.1386 -0.1944
0.1320 0.0960 0.0504 0 -0.0504 -0.0960 -0.1320
0.0840 0.0630 0.0336 0 -0.0336 -0.0630 -0.0840
0.0486 0.0384 0.0210 0 -0.0210 -0.0384 -0.0486
0.0240 0.0210 0.0120 0 -0.0120 -0.0210 -0.0240
0.0084 0.0096 0.0060 0 -0.0060 -0.0096 -0.0084
0 0.0030 0.0024 0 -0.0024 -0.0030 0
-0.0030 0 0.0006 0 -0.0006 0 0.0030
-0.0024 -0.0006 0 0 0.0000 0.0006 0.0024
0 0 0 0 0 0 0
0.0024 0.0006 -0.0000 0 0 -0.0006 -0.0024
0.0030 0 -0.0006 0 0.0006 0 -0.0030
0 -0.0030 -0.0024 0 0.0024 0.0030 0
-0.0084 -0.0096 -0.0060 0 0.0060 0.0096 0.0084
-0.0240 -0.0210 -0.0120 0 0.0120 0.0210 0.0240
-0.0486 -0.0384 -0.0210 0 0.0210 0.0384 0.0486
-0.0840 -0.0630 -0.0336 0 0.0336 0.0630 0.0840
-0.1320 -0.0960 -0.0504 0 0.0504 0.0960 0.1320
-0.1944 -0.1386 -0.0720 0 0.0720 0.1386 0.1944
-0.2730 -0.1920 -0.0990 0 0.0990 0.1920 0.2730
Columns 15 through 21
-0.3360 -0.3750 -0.3840 -0.3570 -0.2880 -0.1710 0
-0.2340 -0.2520 -0.2430 -0.2016 -0.1224 -0.0000 0.1710
-0.1536 -0.1560 -0.1344 -0.0840 0 0.1224 0.2880
-0.0924 -0.0840 -0.0546 0 0.0840 0.2016 0.3570
-0.0480 -0.0330 0.0000 0.0546 0.1344 0.2430 0.3840
-0.0180 0 0.0330 0.0840 0.1560 0.2520 0.3750
-0.0000 0.0180 0.0480 0.0924 0.1536 0.2340 0.3360
0.0084 0.0240 0.0486 0.0840 0.1320 0.1944 0.2730
0.0096 0.0210 0.0384 0.0630 0.0960 0.1386 0.1920
0.0060 0.0120 0.0210 0.0336 0.0504 0.0720 0.0990
0 0 0 0 0 0 0
-0.0060 -0.0120 -0.0210 -0.0336 -0.0504 -0.0720 -0.0990
-0.0096 -0.0210 -0.0384 -0.0630 -0.0960 -0.1386 -0.1920
-0.0084 -0.0240 -0.0486 -0.0840 -0.1320 -0.1944 -0.2730
0 -0.0180 -0.0480 -0.0924 -0.1536 -0.2340 -0.3360
0.0180 0 -0.0330 -0.0840 -0.1560 -0.2520 -0.3750
0.0480 0.0330 0 -0.0546 -0.1344 -0.2430 -0.3840
0.0924 0.0840 0.0546 0 -0.0840 -0.2016 -0.3570
0.1536 0.1560 0.1344 0.0840 0 -0.1224 -0.2880
0.2340 0.2520 0.2430 0.2016 0.1224 0 -0.1710
0.3360 0.3750 0.3840 0.3570 0.2880 0.1710 0
contour(X,Y,Z)
mesh(X,Y,Z)
pcolor(X,Y,Z)
Functions
So far, everything has been executed as a script, or calling a built-in function. Now we begin building our own functions.
Functions are saved in memory (or better yet) in a folder in your path or current directory
Example of storing function in memory
f= @(x,y) (x.*y.^3-x.^3.*y)
f =
@(x,y)(x.*y.^3-x.^3.*y)
f(0.1,-0.5)
ans =
-0.0120
Here we will save a function called my_function
as my_function.m
function [vx,vy] = my_function(x,y,t)
% Help documentation of "my_function"
% This function computes the velocity in the x- and y-directions given
% three vectors of position in x- and y-directions as a function of time
% x = x-position
% y = y-position
% t = time
% output
% vx = velocity in x-direction
% vy = velocity in y-direction
vx=zeros(length(t),1);
vy=zeros(length(t),1);
vx(1:end-1) = diff(x)./diff(t); % calculate vx as delta x/delta t
vy(1:end-1) = diff(y)./diff(t); % calculate vy as delta y/delta t
vx(end) = vx(end-1);
vy(end) = vy(end-1);
end
help my_function
Help documentation of "my_function"
This function computes the velocity in the x- and y-directions given
three vectors of position in x- and y-directions as a function of time
x = x-position
y = y-position
t = time
output
vx = velocity in x-direction
vy = velocity in y-direction
t=linspace(0,10,100)';
x=t.^3; % vx = 3*t^2
y=t.^2/2; % vy = t
[vx,vy]=my_function(x,y,t);
yyaxis left
plot(t(1:10:end),vx(1:10:end),'o',t,3*t.^2)
ylabel('v_{x}')
yyaxis right
plot(t(1:10:end),vy(1:10:end),'s',t, t)
ylabel('v_{y}')
xlabel('time')
Now, create a new function that calls 'my_function' called, my_caller.m
help my_caller
Help documentation of "my_caller"
This function computes the acceleration in the x- and y-directions given
three vectors of position in x- and y-directions as a function of time
x = x-position
y = y-position
t = time
output
ax = velocity in x-direction
ay = velocity in y-direction
[ax,ay]=my_caller(x,y,t);
yyaxis left
plot(t(1:10:end),ax(1:10:end),'o',t,6*t)
ylabel('a_{x}')
yyaxis right
plot(t(1:10:end),ay(1:10:end),'s',t, 1*t./t)
ylabel('a_{x}')
xlabel('time')
axis([0,10,0,3])
diff_match_dims(x,t)
�[0;31mUndefined function 'diff_match_dims' for input arguments of type 'double'.
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