Passing arguments to a lua file in torch-android

[kk291]

Hi,

How are we supposed to pass arguments to a lua file in torch-android?

[borisfom]

This is very confusing question. What exactly are you trying to achieve ?

[paramsen]

This is actually a question regarding Torch and Lua, rather than TorchAndroid. As I understand the question @kk291 wants to know how one can pass for instance a vector (or tensor) to a Torch -script/Lua -script, in AndroidTorch.

Expecting that you have succeeded to add the compiled TorchAndroid .so/.h files to your Android project you can proceed with the following steps. The links refer to relevant lines in the bundled demo source.

1. Create a C or C++ class that handles your integration with TorchAndroid
   1.1) Create necessary initialization/destruction code for TorchAndroid
2. Create a function in this class that can push a Tensor (or data of arbitrary kind) to TorchAndroid [i.e. your lua -file] and read the result

Here's the relevant lines invoking a function in the Lua -script with a Tensor argument:

lua_getglobal(L, "getTopOnly");
luaT_pushudata(L, testTensor, "torch.DoubleTensor");
if (lua_pcall(L, 1, 1, 0) != 0)
    //error, retreive error
else
    //success, retreive result

One needs to know that the C Lua api is stack based, meaning you interact with the Lua inerpreter as you do with a stack, refer to the links to see how.

This is not strictly related to TorchAndroid, but just the C/C++ Lua api.