# Graphing noise (mathematica)

• Mathematica
For my time series and spectral analysis class i need to graph something like in the attachment. i need to have 100 numbers that are connected like that, and then 'add' them to a sinusiodal wave to create a real life wave - with noise.

How would i do this using mathematica??

I can easily generate a whole bunch of random numbers with ranging values but how would i make it such taht all the numbers are in ascending order and go from 0 to at least 2 pi?

would i use numerous Random[x] and then arrange them (how?) in ascending order??

#### Attachments

• noise.JPG
7.1 KB · Views: 312

any ideas people??

graphing random numbers and then 'joinging' them seems to be a good idea here... is that possible with mathematica though?

Look up the function Sort.

Sort[Real,{1.13,2.14,1.54,2.61}]

{1.13,1.54,2.14,2.61}

chroot
Staff Emeritus
Gold Member
I have no idea what you mean, ascending order. From what I can tell, there's no correlation between the time and the value, which is rather the definition of a random variable. You're not going to add the random values to the angles going into the sine function -- you're going to add them to the outputs coming from the sine function.

Just compute a table of sine values, one for each point of interest. Next, add a random value to each entry in the table.

- Warren

chroot said:
I have no idea what you mean, ascending order. From what I can tell, there's no correlation between the time and the value, which is rather the definition of a random variable. You're not going to add the random values to the angles going into the sine function -- you're going to add them to the outputs coming from the sine function.

Just compute a table of sine values, one for each point of interest. Next, add a random value to each entry in the table.

- Warren

now why didnt i think of it that way

in fact tahts what my prof said too

im just silly

thanks a lot