how can i create a 3d-plot from a matrix?

Hi guys, i trying to create a 3d-plot or a waterfall-plot from an excel-table but i cant do it.

Maybe y could help me!.

The problem is that i have 3 variables: Time, frequency and soundpressure (SPL) y can take a look into the attachment.

could y tell me how to make it?

i thank y a lot!

Regards

Nico.

[Walter Roberson]

You have 13 header lines.

Your 14th header line starts with 'Hz' and has a number of values listed after that without indication of meaning. Are those times?

Line 15 to 45 appears to start with a frequency and have a number of readings after that. Are those SPL corresponding to the times from line 14 ?

You have semi-colon delimited values with comma as the decimal separator.

It appears that at higher frequencies you have fewer entries per line.

[Nicolas Ippoliti]

Hi Walter, thanks for your answer!.

Yes, under Hz is the frequenz, after Hz (to the right) its the time (from 0,0098114 s to 13,9941864 s) and between the SPL at this time and at the respectly Frequency band (1/3 Octave).

i tried to resolve it with meshgrid but i couldn't completely understand how its work.

Thank you again!

Regards

Answer 1

[Walter Roberson]

I have attached code.

The data was messier than it looked. There were two half-tables side by side, same times and same frequencies, but with ranges that are somewhat different. The code plots them in different plots, variables SPL1 and SPL2 .

You might want to set YScale to log for the plots, since the frequences increase on a log scale (looks like 10*log10(4) as the exponent)

For the first plot, it is meaningful to set the Z scale to log, as all of the values are positive except for one 0.

For the second plot, there are a number of negative values, so it does not make sense to use log scale.

The top left point in the right hand set of data comes across as exactly 65535 . I was pretty sure that was an indicator of invalid data, so I set that to nan.

[Nicolas Ippoliti]

Hi Walter,

first i want to thank y very much for your support!

the script works propertly. and would know if it posible to have a terz frequency distribution or a octave, i tried to do it over the tick configuration but it is not good as well visible.

i really admire people like you, who is supporting other people.

Thanks a lot, and sorry for my bad English.

Have a nice day!

[Walter Roberson]

I am not sure what a terz frequency distribution is, or an octave for this purpose? Do you want the frequency axes to be labeled with log2 of the frequency?