pages tagged wolfram

Wolfram

Sat, 20 May 2017 21:53:47 +0000

Programming idioms

Caching the result of a time-comsuming computation in a symbol's `DownValue`

ClearAll[f]
f[x_] := f[x] = (Pause[5]; Print["Time consuming definition run!"]; 1);

In[31]:= DownValues[f]
Out[31]= {HoldPattern[f[x_]]:>(f[x]=(Pause[5];Print[Time consuming definition run!];1))}

In[32]:= f[1]//AbsoluteTiming//Timing
f[1]//AbsoluteTiming//Timing
During evaluation of In[32]:= Time consuming definition run!
Out[32]= {0.061456,{5.00291,1}}
Out[33]= {7.*10^-6,{1.*10^-6,1}}

In[34]:= DownValues[f]
Out[34]= {HoldPattern[f[1]]:>1,HoldPattern[f[x_]]:>(f[x]=(Pause[5];Print[Time consuming definition run!];1))}

Haskell and Wolfram Language syntax comparison

Fri, 19 May 2017 02:50:12 +0000

description	Haskell	Wolfram	comment
defining a named function with explicitly named arguments	`incrementInteger :: Int -> Int incrementInteger n = n + 1`	`incrementInteger[n_Integer] := n + 1;`
defining a named function with lambda expression	`incrementInteger :: Int -> Int incrementInteger = \n -> n + 1`	`incrementInteger = Function[{n}, n + 1];`
defining a function with a function name as one of the arguments	`Prelude> increment = \x -> x+1 Prelude> double = \x -> 2*x Prelude> thenDouble someFunc = double . someFunc Prelude> thenDouble increment 3 8`	`In[1]:= double = Function[x, 2x]; increment = Function[x, x + 1]; thenDouble[someFunc_] := Composition[double, someFunc]; In[4]:= thenDouble[increment] Out[4]= Function[x, 2 x]@Function[x, x + 1] In[5]:= (thenDouble[increment])[3] Out[5]= 8`
defining a function with locally definded intermediate functions	`Prelude> :{ Prelude> myFunc1 x = Prelude> let y = sin x Prelude> in cos y Prelude> :} Prelude> myFunc1 pi 1.0 Prelude> :{ Prelude> myFunc2 x = Prelude> cos y Prelude> where Prelude> y = sin x Prelude> :} Prelude> myFunc2 pi 1.0`	`In[1]:= myFunc[x_]:=With[{f=Sin[x]},Cos[f]] myFunc[Pi] Out[2]= 1`	Alternatively, instead of using `With` (for symbolic replacement), use `Module` (for lexical scoping) or `Block` (for dynamic scoping).

Wolfram-related Twitter accounts and the alike

Sat, 07 Mar 2015 02:37:38 +0000

news, blogs, comprehensive
- Wolfram: @WolframResearch
- Wolfram Japan: @WolframJapan
- Wolfram China: @WolframChina
- Wolfram Education: @WolframEdu
- Wolfram Careers: @WolframCareers
- Stephen Wolfram: @stephen_wolfram
- Conrad Wolfram: @conradwolfram
- Wolfram NKS: @WolframNKS
- Wolfram Blog
- Stephen Wolfram Blog
Wolfram Language / Mathematica
- MathematicaTip: @MathematicaTip
- Mathematica SE: @StackMma
- Tweet-a-Program: @wolframtap, archive on Tumblr
- Mathematica Cookbook: @salmangano
- Wolfram Tip: @WolframTip
- Sina Weibo:
  - 面向教育的Mathematica: @面向教育的Mathematica
  - Mathematica_李想: @Mathematica_李想
  - Mathematica 中文使用者: @Mathematica中文使用者
  - Wolfram 语言编程珠玑: @WolframTip
- Mathematica StackExchange community blog
Wolfram|Alpha
- Wolfram|Alpha: @Wolfram_Alpha
- Wolfram Fun Facts: @WolframFunFacts
- Wolfram|Alpha Can't: @wacnt
- WolframAlpha queries: @WA_queries
- Wolfram_Alpha: @Wolfram_Alpha
- Wolfram|Alpha Tumblr
- Wolfram|Alpha blog

pages tagged wolfram

Wolfram

Programming idioms

Caching the result of a time-comsuming computation in a symbol's DownValue

Haskell and Wolfram Language syntax comparison

Wolfram-related Twitter accounts and the alike

Caching the result of a time-comsuming computation in a symbol's `DownValue`