2.1 Entering Variables and Formulae

The input of calculations appears directly in the text program. It is sufficient to write a formula such as M = q * l² / 8 or τ =T_eq/ Wt in any empty line and to call up the "Calculate Line" function.
Unlike spreadsheet calculation programs, no cells are required.
The calculation line can include a preceding text, as the equals sign or the colon character separates this from the formula. The unit of measurement can be specified directly after the formula and separated by a space character.
The program interprets the calculation line completely automatically. Units of measurement, format and decimal places are queried if necessary (it is important to refer to Chapter 2.4 for further information). Dependent values are identified and calculated accordingly.

Note: Various toolboxes assist with data entry.

Declare lines as input lines or locked lines

Calculation lines can now be explicitly declared as input lines. Leading to faster data input as relevant information is specifically queried. The data input assistant takes this option into account and queries only the specified input data while importing templates.

Calculation lines may be locked. Preventing unwanted modifications in those lines. Modifications are only feasible after confirming a security message.

The easiest way for inserting data is via the context menu.

Note: Extras-Display-Show Control labels highlight the lines. Color can be set under Extras-Settings-Program interface-Color of Input lines/Color of saved lines.

Numerical values or texts can be assigned to a variable.

Default values are assigned to a variable by writing the variable name with the relevant value into a blank line
(e.g. D = 100 mm) and calling up the Calculate line function.

If specified, results of calculation lines, summations or the Result single-lined/right function are automatically assigned to a variable. The expression that appears before an equals sign or colon character is automatically interpreted as a variable.

VCmaster identifies all dependencies automatically. If a value is changed, the program recalculates the relevant lines. This feature enables calculation algorithms to be formulated without any programming knowledge.

Validity of variables

The specification made last is decisive. If the same variable is specified a second time, the new value is applied from this point on.

Definition of calculation areas

VCmaster is capable of encapsulating algorithms. Meaning, variables are explicitly assigned a specific validity range, thus minimizing the risk of confounding variables, especially when several similar calculations are repeated.
This significantly speeds up calculations.

Variable names

Can be of any length and must always begin with a letter,
(Important tip: Please note that the documents transferred from other countries with country specific characters can be interpreted incorrectly if the country settings in windows-systems are different. This is especially encountered when the code page is different for e.g. east and west Europe.)
May only contain numerical values and alphabetical characters (including Greek characters and umlauts); the following special characters are allowed: full stop, comma, infinity, underscore and square brackets.
Several characters are inadmissible including superscript characters, round brackets, semicolons and mathematical operators. The following variables cannot be interpreted mathematically: h² = ... ; b/2 = ... ; X(20) = ...

Exception: Expressions in square brackets will not be interpreted mathematically so that variables like M_[G+Q] are possible.

Not allowed		Error because the ...	Allowed
h² =	100 mm		h =	10 mm
X =	h²	... variable h is missing	X =	h²	= 100	.00 mm²

b/2 =	20 mm		b =	40 mm
b1 =	b/2	... variable b is missing	b1 =	b/2	= 20	.00 mm

F(10) =	500 N		F_[10] =	500 N
σ =	F(10)/A	... operator * is missing	σ =	F_[10] / A	= 10	.00 N/mm²
		[Tip: VCmaster expects F * ( ... ) ]

Normal and subscript characters are not differentiated (h1 = h₁).

Specification of a variable

10 mm

Text variable (e.g. for materials and database queries):

Selected bolt=

"M12"

Formula without text:

F/A=	10.00 N/mm²

Formula with text (terminated by an equals sign) and variable allocation:

Stress σ_v =	Re * a / 100	= 846.00 N/mm²
max. moment M =	q* L² / 8	= 5.56 kNm

Graphic formula with variable allocation (k90):

Coefficient k90 =

= 0.59

Simple example from a structural analysis:

2.1 Entering Variables and Formulae

2.1.1 Principle of the Calculation Lines

BUTTON:

HOTKEY:

MENÜ:

Graphic formulae

BUTTON:

HOTKEY:

MENÜ:

Representation of formulae

Declare lines as input lines or locked lines

2.1.2 Definition of Variables

Validity of variables

Definition of calculation areas

MENÜ:

Variable names

2.1.3 Examples