Question

matlab question

Answer 1

%% 5.5
% Adjust the plot created in Problem 5.4 so that the x-axis goes from -6
% to +6.
% Add a legend
% Add a text box describing the plots.

x = -6:0.05:6; % new x-axis from -6 to +6

% sin functions y1, y2, and y3
y1 = sin(x);
y2 = sin(2*x);
y3 = sin(3*x);
% sins plotted (Lines 1-3)
plot(x, y1, 'r--', x, y2, 'b', x, y3, 'g:');
legend('y1', 'y2', 'y3');

% txt box for y1
y1 = sin(pi);
x1 = pi;
txt1 = '\leftarrow sin(pi) = 0';
text(x, y1, txt1);

Answer 2

How do I code the textbox? I was looking at mathworks site and found an example, however it displays many equation along the sine wave which isn't what I want.

Answer 3

@jim_thompson5910

Answer 4

So you just want the textbox to say `\leftarrow sin(pi) = 0` ?

Answer 5

how exactly do you want this text box to look? I'm assuming you want it on your graph somehow?

Answer 6

I actually got it figured out

Answer 7

ok great

Answer 8

but I am a little confused still.

Answer 9

% txt box for y1
y1 = sin(x);
x1 = pi;
txt1 = '\leftarrow sin(\pi) = 0';
text(pi/12, 0, txt1);

Answer 10

what's not making sense?

Answer 11

text(pi/12, 0 txt1) as I increase the 12 the arrow shift to the left. I used pi at first and the arrow was located at the end of the graph on the right side at y = 0

Answer 12

so what is pi/12 doing is this the x-axis per say?

Answer 13

so in this case, the textbox is placed at (pi/12, 0). That part I'm sure of. The part I'm not sure of is where the reference point on the texbox is. Is it in the left upper corner? center? I don't know

Answer 14

no it doesn't say specific. I took that example from mathworks site

Answer 15

we can place them wherever we want.

Answer 16

`as I increase the 12 the arrow shift to the left`
so what you're doing is making the x coordinate (of where you're placing the textbox) smaller. Which means it shifts more towards 0. So more to the left on the x axis number line

Answer 17

I'm sure you've probably seen this example already

http://www.mathworks.com/help/examples/graphics/LabelPointOnGraphExample_01.png

the code for it is

text(pi,0,'\leftarrow sin(\pi)')

so this textbox is placed at (pi,0)

Answer 18

I was looking at that now. I will play around with this some more. I think I understand and can apply text box to the other two graphs now. Thanks

Answer 19

no problem

Answer 20

@jim_thompson5910

Answer 21

is there anyway to just show that graph 1 is y1 = sin(x) , y2 = sin(2x), and y3 = sin(3x) ?

Answer 22

you mean plot them all on the same coordinate grid?

Answer 23

nvm it works now

Answer 24

it wasn't working before.

Answer 25

This is what I wanted the text to say and it works now. At first the arrow was there it just displayed leftarrow