Console output for predictions

[sebastien-fauvel]

It would be interesting, for performance reasons, that applications using svm-predict to classify single documents were able to pass the document to classify as a command line argument (instead of a file name), and that the predicted class be printed directly to the output (instead of writing it to a file). This would spare lots of useless IO operations.

What about adding a new usage:

svm-predict [options] test_document model_file

with a console output, for instance:

$ svm-predict '1:-0.14 2:0.2666667 3:0.1074111' model.svm
-1

[kritzikratzi]

should be quite easy to create this yourself.
roughly like this:

char * path = "classifier.model"; 
svm_model * model = svm_load_model(path);

svm_node * nodes = new svm_node[3]; // num features + 1 
nodes[0].index = 1; 
nodes[0].value = featureValue1; 
nodes[1].index = 2; 
nodes[1].value = featureValue2; 
nodes[2].index = -1; // mark end

int result = svm_predict(model, nodes); 
delete [] nodes; 
svm_free_and_destroy_model(&model);

// now do something with the result ... 

[sebastien-fauvel]

Thank you for the input! I'll definitely look into this at some point.

[tavianator]

You could also use /dev/stdin and /dev/stdout as the filenames (probably, haven't checked that it works).

[sebastien-fauvel]

Oh my bad! It actually works :)

> printf "1 1:10\n2 1:20\n" > model.dat
> svm-train -q -g 1 model.dat model.svm
> echo '0 1:20' | svm-predict -q /dev/stdin model.svm /dev/stdout
2

Thank you so much!