Simply reading a csv file

Programming Questions

daniela19..

in Programming Questions • 2 years ago

Hey everyone!

I am more than new to this processing world. At the first look it seems hard an confusing. To be honest I preffer java or python. But, I have to do this project and I need to use processing. To start with, I am trying to read data from a csv file (i.e. excel file). The csv file has just a column of numbers inside, nothing complicated. Do you have any idea how to do that? and do you know any online good tutorials on processing? Thank you!

Replies(11)

clankill3r

Re: Simply reading a csv file

2 years ago

I didn't test it but it's something like this:

String[] lines = loadStrings("somefile.csv");

for(int i = 0; i < lines.length; i++){
      String[] tokens = splittokens(lines[i], ';');
      int x = int(tokens[0]);
      String abc = tokens[1];
}

daniela19..

Re: Re: Simply reading a csv file

2 years ago

Thanks!

I didn't have to try it either but it looks useable! haha

Thank you for the quick reply! I'll probably come back with more silly questions.

Daniela

daniela19..

Re: Re: Simply reading a csv file

2 years ago

Ok,

So I just tried your code and it gives some errors. But, what can I tell you is that I think I managed to read csv. Here's the code:

String filename=dataPath("whitenoise.csv");
println("--readfile--");
try {
BufferedReader reader = new BufferedReader (new FileReader (filename)) ;
while (true) {
      String lineIn = reader.readLine() ;
      if (lineIn==null) break;
      println(lineIn);
    }
}

You can try and see if it works for you. The whitenoise.csv contained just one column of numbers. The thing is, that I think that what I am doing now, is just reading it in 'string mode'. Which means, that I can't really use the numbers in the file to do mathematical calculations. So I still have to work on that.

If you have any ideas, please let me know :)

Cheers,

Daniela

Hey,

I managed to do eveything! I am quite happy! :)

radiodario

Re: Simply reading a csv file

2 years ago

to be honest, processing is java. if you feel more comfortable in a traditional IDE, you can always use eclipse to write processing. It also makes the whole business of using external libraries much easier. You could then pick up a CSV reading library for java, or something like that.

But clankill3r's method works just fine. And loadStrings is pretty useful because it can also load URL's! You can use split() or splitTokens() like clankill3r shows

String [] lines = loadStrings("somefile.csv");
for (String line : lines) {
String[] pieces = split(line, ',');
// do something with each field
}

cheerio

Dario

PROTIP: read the DOCUMENTATION. Processing has one of the best documented codebases out there. Use it!

daniela19..

Re: Re: Simply reading a csv file

2 years ago

Thank you for the reply!

I m on a different time zone that's why it took me so long to respond! And also for the tips, I didn't get to the point where to read documentation and follow tutorials because my boss just expected me to know everything from the first day!

Thanks again!

Daniela

rapatski

Re: Simply reading a csv file

2 years ago

Well, clankill3r, I wouldn't call the result from split() "tokens", as tokens are what's been splitted on.
Wow Dario.. that for(String line : lines) is pretty fancy! Didn't know that one!

Tutorials.. plenty. Have you checked out http://processing.org/learning/ ?!

radiodario

Re: Re: Simply reading a csv file

2 years ago

Fixed! I copy-pasted it from one of my programs and i forgot to change that variable.

the For-Each loop is a nifty construct except for occasions in which you need to keep track of the index of the current iteration, but it just looks nicer.

rapatski

Re: Re: Simply reading a csv file

2 years ago

I didn't know Processing had one. Nice.

daniela19..

Re: Re: Simply reading a csv file

2 years ago

Hey,

will do, thank you for the tip ;)

Daniela

daniela19..

Re: Simply reading a csv file

2 years ago

Hey everybody,

Thank you for all the replys! I managed to do everything I wanted so far!! I am happy, which is sad hahaha I get happy over a code, sad, sad, sad :)

Thank you for all the help!

Cheers,

Daniela

PhiLho

Re: Re: Simply reading a csv file

2 years ago

You are not happy over a code, you are happy to succeed in your difficult enterprise, overcoming a delicate problem. That's different... It is called self-esteem!

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