Re: peaks and valleys plot

[Rick T]

thanks but it comes back with an error

parse error near line 10 of file test_plot.m

syntax error

>>> [~, mn] = min (yf);

^

>>>error: source: error sourcing file `test_plot.m'

this was the code I used

t= linspace(0,2*pi,8000);

freq=10;

y=sin(t*freq)+cos(t*freq*1.3);

y=y';

y2=y*3+y*4+y*2;

yf=(y2(:,1)/max(abs(y2(:,1)))*1); %keep at 1, amplitude levels

%plot(yf)

[~, mn] = min (yf);

[~, mx] = max (yf);

plot (t, yf, t(mn), yf(mn), "s", t(mx), yf(mx), "s")

text (t(mn), yf(mn), sprintf ("min = %f", yf(mn)), "verticalalignment", "top", "horizontalalighment", "center")

text (t(mx), yf(mx), sprintf ("max = %f", yf(mx)), "verticalalignment", "bottom", "horizontalalighment", "center")

On Fri, Dec 30, 2011 at 2:19 PM, Ben Abbott <address@hidden> wrote:

On Dec 30, 2011, at 7:08 PM, Rick T wrote:

> Greetings All
>
> I'm trying to have the x value and y value next to the peak and valley on a plot can someone assist
>
> t= linspace(0,2*pi,8000);
> freq=10;
> y=sin(t*freq)+cos(t*freq*1.3);
> y=y';
> y2=y*3+y*4+y*2;
> yf=(y2(:,1)/max(abs(y2(:,1)))*1); %keep at 1, amplitude levels
> plot(yf)

I haven't tested this.

[~, mn] = min (yf);
[~, mx] = max (yf);
plot (t, yf, t(mn), yf(mn), "s", t(mx), yf(mx), "s")
text (t(mn), yf(mn), sprintf ("min = %f", yf(mn)), "verticalalignment", "top", "horizontalalighment", "center")
text (t(mx), yf(mx), sprintf ("max = %f", yf(mx)), "verticalalignment", "bottom", "horizontalalighment", "center")

Ben