yasnippets for jasp, ase and python

Posted February 17, 2014 at 09:03 AM | categories: ase, jasp, emacs | tags:

In using [[http://github.com/jkitchin/jasp for calculations, I find there are lots of small python phrases I use over and over. Today I will examine using yasnippet to save time and keystrokes. yasnippet is a template expansion module, where you type a small set of characters, press Tab, and the characters "expand" to the full text. It is pretty sophisticated, and allows you to define "tab-stops" which you interactively fill in, and tab between like filling in a form.

All the snippets are defined in the 

*Appendix
.

1 Tangle the snippets, and add them to yasnippet

Each snippet definition belongs in a file in a directory. The main directory is called "snippets". Since I anticipate using these snippets in org-mode, each snippet is defined in a directory within snippets called "org-mode". First, we make the directory here. I also want to use the snippets in python mode, so we also create a python-mode directory here. We do not have to duplicate the snippets. We can create a file called .yas-parents , with one line in it containing "org-mode". 

mkdir -p snippets/org-mode
mkdir -p snippets/python-mode
echo "org-mode" > snippets/python-mode/.yas-parents

Each snippet is defined in a src block with a :tangle header. So, we can extract them all in one command here. 

(org-babel-tangle)
snippets/org-mode/iase snippets/org-mode/imp snippets/org-mode/inp snippets/org-mode/ij snippets/org-mode/pl snippets/org-mode/pyl snippets/org-mode/pxl snippets/org-mode/pp snippets/org-mode/npa snippets/org-mode/awt snippets/org-mode/avw snippets/org-mode/agf snippets/org-mode/ape snippets/org-mode/atms snippets/org-mode/atm snippets/org-mode/cga snippets/org-mode/cc snippets/org-mode/wjn snippets/org-mode/wjl

We also need to add our new directory to yasnippets. This is done by adding the directory to the yas-snippet-dirs variable. You could add this to your init.el file to permanently add these snippets. 

(add-to-list 'yas-snippet-dirs "c:/Users/jkitchin/Dropbox/blogofile-jkitchin.github.com/_blog/snippets")
c:/Users/jkitchin/Dropbox/blogofile-jkitchin.github.com/blog/snippets ~/.emacs.d/snippets c:/users/jkitchin/Dropbox/kitchingroup/jmax/elpa/yasnippet-20140106.1009/snippets

Finally, we reload all the snippet definitions, so our new definitions are ready to use. 

(yas-reload-all)

[yas] Reloaded everything (snippets will load just-in-time)... (some errors, check *Messages*).

Alternatively, you might just load this directory. 

(yas-load-directory "./snippets")

2 Using the snippets

Each of these snippets is for a python phrase, but I usually write my python blocks in org-mode. You would use these by typing the shortcut name, and then pressing tab. Below I show what each shortcut expands to.

wjl → with jasp('') as calc:

wjn → with jasp('',) as calc: calc.calculate(atoms)

cc → calc.calculate(atoms)

cga → atoms = calc.get_atoms()

atm → Atom('', )

atms → atoms = Atoms([], cell)=

ape → atoms.get_potential_energy()

agf → atoms.get_forces()

avw → from ase.visualize import view view(atoms)

awt → from ase.io import write write('.png', atoms, show_unit_cell=2)

npa → np.array()

pp → plt.plot(, )

pxl → plt.xlabel()

pyl → plt.ylabel()

pl → plt.legend()

ij → from jasp import *

inp → import numpy as np

imp → import matplotlib.pyplot as plt

iase → from ase import Atom, Atoms

What other snippets would be handy?

3 Appendix

3.1 jasp snippets

# -*- mode: snippet -*-
# --
with jasp('$1') as calc:
    $0

# -*- mode: snippet -*-
# --
with jasp('$1',$0) as calc:
    calc.calculate(atoms)

# -*- mode: snippet -*-
# --
calc.calculate(atoms)

# -*- mode: snippet -*-
# --
atoms = calc.get_atoms()

3.2 ase snippets

Template for an ase.Atom 

# -*- mode: snippet -*-
# --
Atom('$1', $2)

# -*- mode: snippet -*-
# --
atoms = Atoms([$1], cell=$2)

# -*- mode: snippet -*-
# --
atoms.get_potential_energy()

# -*- mode: snippet -*-
# --
atoms.get_forces()

# -*- mode: snippet -*-
# --
from ase.visualize import view
view(${1:atoms})

# -*- mode: snippet -*-
# --
from ase.io import write
write('$1.png', ${2:atoms}, show_unit_cell=${3:2})

3.3 python snippets

# -*- mode: snippet -*-
# --
import numpy as np

# -*- mode: snippet -*-
# --
import matplotlib.pyplot as plt

# -*- mode: snippet -*-
# --
from ase import Atom, Atoms

# -*- mode: snippet -*-
# --
np.array($0)

# -*- mode: snippet -*-
# --
plt.plot($1, $2)

# -*- mode: snippet -*-
# --
plt.xlabel($1)

# -*- mode: snippet -*-
# --
plt.ylabel($1)

# -*- mode: snippet -*-
# --
plt.legend($1)

# -*- mode: snippet -*-
# --
from jasp import *

Copyright (C) 2014 by John Kitchin. See the License for information about copying.

org-mode source

Org-mode version = 8.2.5h

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