---
title: "Installation"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Installation}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

## PyTorch installation

### Installing Python and PyTorch

Although, *Python* and *PyTorch* can be installed directly from the *R* console, before start running `rTorch`, I would recommend testing **PyTorch** first in a new Python or Anaconda environment. Check if PyTorch and Torchvision packages are imported alright. The advantage of doing it this way is that you could have already in advance a PyTorch version that you are sure is working alright.

If you prefer to install PyTorch and its dependencies, that can be done from **rTorch** through one its functions `install_pytorch()`.

### rTorch functions to install PyTorch

#### install_pytorch

This function is public and can be invoked with `rTorch::install_pytorch()`.

This function will allow you to indicate (i) the Python version; (ii) the PyTorch version; (iii) the name of the conda environment; (iv) which channel (`stable` or `nightly`); (v) if you require CUDA (GPU) computation; (vi) additional packages such as `matplotlib`, `pandas`; (vii) more.

    install_pytorch(
      method = c("conda", "virtualenv", "auto"),
      conda = "auto",
      version = "default",
      envname = "r-torch",
      extra_packages = NULL,
      restart_session = TRUE,
      conda_python_version = "3.6",
      pip = FALSE,
      channel = "stable",
      cuda_version = NULL,
      dry_run = FALSE,
      ...
    )

## Manual installation of *PyTorch* in a *conda* environment

If you prefer do it manually, use this example:

1.  Create a conda environment with `conda create -n my-torch python=3.7 -y`

2.  Activate the new environment with `conda activate my-torch`

3.  Inside the new environment, install *PyTorch* and related packages with:

`conda install python=3.6 pytorch torchvision matplotlib pandas -c pytorch`

> Note: If you you don't specify a version, `conda` will install the latest *PyTorch*. As of this writing (August-September 2020), the latest *PyTorch* version is 1.6.

Alternatively, you could create and install a *conda* environment a specific **PyTorch** version with:

`conda create -n my-torch python=3.6 pytorch=1.3 torchvision matplotlib pandas -c pytorch -y`

`conda` will resolve the dependencies and versions of the other packages automatically, or let you know your options.

**Note.** `matplotlib` and `pandas` are not really necessary, but I was asked if `matplotlib` or `pandas` would work in PyTorch. Then, I decided to put them for testing and experimentation. They both work.

## Automatic Python detection

In **rTorch** there is an automatic detection of *Python* built in in the package that will ask you to install `Miniconda` first if you don't have any Python installed in your machine. For instance, in `macOS`, Miniconda will be installed under `PREFIX=/Users/user_name/Library/r-miniconda`.

After *Miniconda* is installed, you could proceed to install the flavor or *PyTorch* you want, and the packages you want, with a command like this:

    rTorch:::install_conda(package="pytorch=1.4", envname="r-torch", conda="auto", conda_python_version = "3.6", pip=FALSE, channel="pytorch", extra_packages=c("torchvision", "cpuonly", "matplotlib", "pandas"))

The command above will install the **stable** **PyTorch 1.4** version on **Python 3.6**, including three additional packages: `torchvision`, `cpuonly`, `matplotlib` and `pandas.`

> NOTE. My experience with `Miniconda` is spotty and not 100% reliable, specially in *macOS*. I would strongly recommend using full *conda* for your PyTorch installation.