tueda

(*
 * Defines the given symbol if it has not been defined. For the value of the
 * symbol, this function tries to load it from the given environment variable.
 * The optional third argument is the default value which is used when the
 * environment variable is undefined. This function returns the value of the
 * symbol if defined, otherwise returns $Failed.
 *)
LoadVariable[symbol_, env_String, default_:Null] := (
  If[!ValueQ[symbol],
    If[Environment[env] =!= $Failed,

tueda

**
* The extended euclidean algorithm, which gives x and y such that
*   a*x + b*y = gcd(a, b) >= 0.
* Input: Integers $a and $b.
* Output: Integers $x and $y.
*
#procedure ExtGCD(a,b,x,y,tmp1,tmp2,tmp3,tmp4,tmp5,tmp6)
  #define aa    "`tmp1'"
  #define bb    "`tmp2'"
  #define lastx "`tmp3'"

tueda

#! /bin/sh

# Prints the absolute path to the directory containing the given path.
# The directory must exist.
abs_dirname() {(
  cd "`dirname \"$1\"`" && pwd
)}

# Examples

tueda

#! /bin/sh

# Wraps "mktemp -d $1XXXXXXXXXX"
mktemp_d() {(
  umask 077
  {
    # Use mktemp if available.
    dir=`mktemp -d "$1XXXXXXXXXX" 2>/dev/null` && [ -d "$dir" ]
  } || {
    # Fall back on mkdir.

tueda

(*
 * Evaluates the given expression with printing the timing in the real time.
 *)
Time[expr_] := Module[{t, r},
  {t, r} = AbsoluteTiming[expr];
  Print["Elapsed time: ", t, " seconds."];
  r
];
SetAttributes[Time, HoldFirst];

tueda

# append_path VAR PATH - adds PATH to the end of PATH
append_path() {
  [ $# -lt 2 ] && return
  [ ! -d "$2" ] && echo "Warning: path $2 is not found on `hostname`" >&2
  remove_path $1 $2
  if eval '[ -z "$'$1'" ]'; then
    eval $1=$2
  else
    eval $1='$'$1:$2
  fi

tueda

CF den;
S x;
S a,j,n,x1,x2;

S a,b,c;

L F1 = den(1-x);
L F2 = den(1-x)^2 / x;
L F3 = den(a+b*x      );
L F4 = den( +b*x+c*x^2);

tueda

/*
 * This snippet uses C++11 features. For C++03, see the previous revision.
 *
 * Replace idioms like
 *
 *   struct Foo {
 *     int a;
 *   };
 *
 *   void func(Foo *f) {

tueda

CC       = gcc
CFLAGS   = -g -O2 -Wall -Wextra -std=c90 -pedantic
CXX      = g++
CXXFLAGS = -g -O2 -Wall -Wextra -std=c++98 -pedantic
F77      = gfortran
FFLAGS   = -g -O2 -Wall -Wextra -std=f95 -pedantic
FC       = gfortran
FCFLAGS  = -g -O2 -Wall -Wextra -std=f95 -pedantic
CPPFLAGS =
DEFS     =

tueda

filesize() {
  if [ -f "$1" ]; then
     wc -c "$1" | awk '{print $1}'
  else
    echo "filesize: file $1 doesn't exist" >&2
    return 1
  fi
}