Performance

[Graham]

I have been trying different libraries for math parsing, including, Exp4j, Jeval, Jep and Mesp.

my performance is focused on the android development, and currently I have only tested on the Android emulator (slow as sin) and I have to say that Mesp has the best performance of the group, although it is the only one currently set up with a ExpressionTree, I believe jeval also has expression tree, so I have yet to properly test it.

BUT, I just wanted to say that this library is very very fast and awesome to use.

so far (in seconds on android emulator without debug, 1000 iterations):

Exp4j Average Time: 0.014022999999999999
Jeval Average Time: 0.027663
Jep Average Time:   0.010093
MESP Average Time:  0.0021469999999999996

now to see if I can figure out if the rest of the libraries have ExpressionTree implementations.

Thanks!

[Graham]

I couldn't find an edit button sooo…. double post :-)

I took a bit to figure out more efficient methods to do the calculations for the other libraries and I ended up with this:

Exp4j Average Time: 0.00071
Jeval Average Time: 0.02689
Jep Average Time:   0.00072
MESP Average Time:  0.00237

so it seems it comes in third on the emulator, I plan on testing it on my android device, but I am still in the process of finding more libraries to test.

also if you could suggest a faster way of doing this, that would be awesome!

public double TestMesp(String Function, int repeatCount)
    {
        double startTime = 0;
        double totalTime = 0;
        double count = 0;

        String s = "floor((Right+1-Left)/2)";
        Expression x = ExpressionTree.parse(s);

        VarMap vm = new VarMap(false /* case sensitive */);

        FuncMap fm = new FuncMap(); // no functions in expression

        for (int i = 0; i < repeatCount; i++) {
            startTime = System.currentTimeMillis();
            
            vm.setValue("Right", 60);
            vm.setValue("Left", 20);
            fm.loadDefaultFunctions();
            x.eval(vm, fm);

            totalTime += (System.currentTimeMillis() - startTime);
            count++;
        }

        return (totalTime / count) / 1000.0;
    }

ps, the setValue inside the loop is purposeful, I want it to be as if the code is looping through an excel sheet grabbing the current values in the row etc…

[Graham]

ooops one small correction, it WAS the fastest i had the fm.loadDefaultFunctions() inside the loop!

now it ends up with:

MESP Average Time: 0.00029

fantastic speed!!