STAAD.Pro Help

M. Formula Calculation window

Used for holding evaluations under the formulas, which are set by the user in the window of lead

Formula calculation window

Formula Syntax

At lead of the formulas it is necessary to observe the following rules:

  • the names of functions are entered by lower case letters of the Latin alphabet;
  • a separator of fractional and whole parts of number is the point;
  • the arithmetical operations are set by characters +, -, *, /, exponentiation ^ (for example, 2.5*2.5*2.5 is typed as 2.5 ^ 3).

Supported Functions

At record of the formulas it is possible to use the following functions:
  • floor - the greatest integer not exceeding preset
  • tan - a tangent
  • sin - sine
  • cos - cosine
  • asin - an arcsine
  • acos - an arccosine
  • atan - an arctangent
  • exp - an exponential curve
  • ceil - the least integer exceeding preset
  • tanh - a tangent hyperbolic
  • sinh - sine hyperbolic
  • cosh - cosine hyperbolic
  • log - a Napierian logarithm
  • log10 - a Brigg's logarithm
  • abs - an absolute value
  • sqrt - the radical square

Depending on a state of the switch Degrees / radians, arguments trigonometrically functions (sin, cos, tan) and the outcomes return trigonometrically functions (asin, acos, atan) are reduced in degrees or radians accordingly.

Usage only of parenthesizes is admitted at arbitrary depth of an enclosure.


The formula:

1.2 + sin ( 0.43 ) + 6.7 6.8 0.003 5
is typed as follows:

1.2+sin (0.43) +6.7*sqrt (6.8) -0.003 ^ 0.2

Click Variable and then the x, y, and z fields become active. Thus values of variables are set in appropriate windows of lead. It allows to carry out a series of one-type evaluations at different values of parameters. For example, in this condition the following formula

1.2 + sin ( x ) + 6.7 6.8 y 5
is typed as follows:

1.2+sin (x) +6.7*sqrt (6.8) -y ^ 0.2

Then click Calculate to have the program resolve the variables into the formula.

Click Copy to copy the result to the Windows clipboard.

Moreover, the program allows to input some symbolic expression (depending on the variables x,y,z); click f x , f y , or f z and retrieve symbolic expression for the corresponding partial derivative.