HyperFun: Statements

There are four types of the statements each ending with ';':

• Assignment statement for a variable
• Assignment statement for an array
• Conditional statement
• Iterative statement

• Assignment statement for a variable.

Its general form is:

<localVarName> '=' <functional expression> ';'

Here <localVarName> is a name of any local variable (including name of array's element) or a name of a coordinate variable.
Examples:

i = 1;
i = i + 1;
x1 = x[1] + a[1];
Metric[2] = b + aa[I]* exp(-sqrt(xx1^2 + x[2]^3);
StrangeBody = Head | (Hand[1] & Leg[2]);
sphere1 = Sphere(x,a);
• Assignment statement for an array.

This statement allows to assign values to all elements of array. Its general form is:

<ElemArrayName> '=' '[' <constant>, ..., <constant> ']' ';'

Example:

pz = [100., -20, 2, 0., 0., -3, 0., 0., 1E-10];

• Conditional statement

It is a traditional 'if-then-else' statement having two forms:

• 'if' <boolean expression> 'then' <statements> 'endif' ';'

• 'if' <boolean expression> 'then' <statements> 'else' <statements> 'endif' ';'

Example:

if (x[4]= 0) then metamorph = CSGobject;

else if (x[4] = 1) then metamorph = blobbyobject;


endif;

endif;
• Iterative statement

The iterative statement allows to define repeating loops. Its general form is:

'while' '(' <boolean expression> ')' 'loop' <statements> 'endloop' ';'

Example:

i=1;

while (i<10) loop

xt[i] = x[1] - x0[i];
i = i+1;

endloop;