deff

Arguments

x, y, in1, in2, ...

input arguments of the defined function. This one can have any number of input arguments, from 0 to any N.

r, r1, r2, ...

Output results of the defined function. This one can have any number of output results, from 0 to any M. If any, all output arguments must be explicit = written on the left-hand-side of the function name.

funcHeadline

Single string: Function's headline = its first line giving the local function's name and the lists of its right-hand-side input arguments and left-hand-side output arguments. Examples:

• "myFunction(x,y)" : no output
• "r = myFunction(x,y)" : single output
• "[a,b] = myFunction(x,y)" : two outputs. Etc..

Please note that a) the function keyword must not be provided. b) If any, writting output arguments in the left-hand-side part of the headline is mandatory.

funcBody

a vector of texts = Scilab instructions of the function's body, in the order they must be executed. These instructions must define and assign the value of all output arguments. No trailing "endfunction" keyword is expected.

This vector is expected when deff(…) is called with two input arguments.

Single or double quotes included in instructions must be doubled to be protected.

definition

Single text or vector of texts, including both the function's headline and body.

• If it's a vector, it is equivalent to definition = [funcHeadline ; funcBody].
• Otherwise, the one-string definition is equivalent to funcHeadline + " " + strcat(funcBody,"; ").

Please see the Description and Examples sections.

myFunc

Public name and identifier of the defined function, as implicitly returned in the current environment, or explicitly assigned to the deff(…)'s output variable.

When deff(…) is called without explicit output argument but as an element of a container or as input argument of another function, it is implicitly assigned to this element or argument, which is anonymous. It is then an anonymous function. Example: L = list(3, deff("r=noName(x) x.^2+1"), "Hello");. The result of deff(…) is assigned to L(2). Then, L(2)(3.5) // ➜ 13.25.

Description

deff(…) can be used to define a single function from Scilab instructions provided through a matrix of text, instead of through any external text file of instructions written in a function … endfunction block to be executed.

A source file of Scilab code can include the definition of several public functions. This is not possible with deff(…): Only one public function can be defined. However, as with a file, the body of the defined function can include one or several function … endfunction blocks defining some nested private functions.

Whatever is the deff(…) syntax used to provide the source code (see below), if this one includes a syntax error, deff(…) will yield a compilation error and stop.

Examples

deff('x = myplus(y,z)', 'x = y+z')
myplus(1,%i)

deff('[y, z] = mymacro(x)', ['y = 3*x+1'; 'z = a*x + x.^2'])
a = 3;
[u, v] = mymacro(2)

--> deff('x = myplus(y,z)', 'x = y+z')
--> myplus(1,%i)
 ans  =
   1. + i

--> deff('[y, z] = mymacro(x)', ['y = 3*x+1'; 'z = a*x + x.^2'])
--> a = 3;
--> [u, v] = mymacro(2)
 v  =
   10.

 u  =
   7.

clear myFunc
source = ["r = myFunc(x,y)" ; "r = x.*(x-y)"]
deff(source)
myFunc(3, -2)

--> source = ["r = myFunc(x,y)" ; "r = x.*(x-y)"]
 source  =
  "r = myFunc(x,y)"
  "r = x.*(x-y)"

--> deff(source)
--> myFunc(3, -2)
 ans  =
   15.

clear myFunc
deff "r = myFunc(x,y) r = x.*(x-y)"
myFunc(1:3, -2)

--> deff "r = myFunc(x,y) r = x.*(x-y)"
--> myFunc(1:3, -2)
 ans  =
   3.   8.   15.

clear myFunc
deff "r = myFunc(x,y) x.*(x-y)"
myFunc(1:3, -2)

--> deff "r = myFunc(x,y) x.*(x-y)"
--> myFunc(1:3, -2)
 ans  =
   3.   8.   15.

clear myFunc
deff("myFunc(x, y) messagebox(prettyprint(x.*(x-y), ""html"",""""))")
myFunc([1 2 ; 3 4], -2)

clear myFunc actualName
actualName = deff("r = myFunc(x,y) x.*(x-y)")
isdef(["myFunc" "actualName"])
actualName(1:3, -2)
myFunc(1:3, -2)

--> actualName = deff("r = myFunc(x,y) x.*(x-y)")
 actualName  =
[r]=actualName(x,y)

--> isdef(["myFunc" "actualName"])
 ans  =
  F T

--> actualName(1:3, -2)
 ans  =
   3.   8.   15.

--> myFunc(1:3, -2)
Undefined variable: myFunc

clear actualName
actualName = deff("r = @(x,y) x.*(x-y)");
actualName(1:3, -2)

--> actualName = deff("r = @(x,y) x.*(x-y)");
--> actualName(1:3, -2)
 ans  =
   3.   8.   15.

L = list("abc", deff("r = @(x,y) x.*(x-y)"), %z);
L(2)(1.1:4, -2.1)
// We can extract and set a name to the anonymous function:
Abc = L(2)
Abc(1.1:4, -2.1)

--> L = list("abc", deff("r = @(x,y) x.*(x-y)"), %z);
--> L(2)(1.1:4, -2.1)
 ans  =
   3.52   8.82   16.12

--> Abc = L(2)
 Abc  =
[r]=Abc(x,y)

--> Abc(1.1:4, -2.1)
 ans  =
   3.52   8.82   16.12

function r=test(txt, x, theFunc)
    r = x + theFunc(txt)
endfunction

test(rand(2,3), 0.7, deff("r = @(M) sum(size(M).^2)"))

--> test(rand(2,3), 0.7, deff("r = @(M) sum(size(M).^2)"))
 ans  =
   13.7

See also

• function — 関数定義をオープンする
• exec — スクリプトファイルを実行する
• getd — ディレクトリで定義された全ての関数を取得する
• genlib — builds a library from a set of *.sci files defining functions in a given directory
• jdeff — 静的JavaメソッドをScilabマクロにマップ
• jcompile — Javaコードまたはファイルをコンパイルする

History