JDSP website states:
JDSP is written purely in Java. It has dependencies on 3 core libraries: Apache Commons Math, IIRJ and SSJ , all of which are also open source projects.
You need (at least for you sketch) these additional JAR files in your code folder in your sketch:
I only needed the last import for your example:
//import com.github.psambit9791.jdsp.misc.*;
//import com.github.psambit9791.jdsp.io.*;
//import com.github.psambit9791.jdsp.speech.*;
//import com.github.psambit9791.jdsp.splines.*;
//import com.github.psambit9791.jdsp.filter.*;
//import com.github.psambit9791.jdsp.filter.adaptive.*;
//import com.github.psambit9791.jdsp.windows.*;
//import com.github.psambit9791.jdsp.transform.*;
//import com.github.psambit9791.jdsp.signal.*;
//import com.github.psambit9791.jdsp.signal.peaks.*;
import com.github.psambit9791.jdsp.filter.Butterworth; // Specific import for Butterworth
And voila!
You will have to add code to plot results:
This was with some modifications to your code:
I will leave it with you to find those jar files in here (I used these) or links on JDSP site:
- Maven Central: com.github.psambit9791:jdsp
- Maven Central: org.apache.commons:commons-math3
- Maven Central: uk.me.berndporr:iirj
This was a fun and worthwhile!
I learned a lot!
:)