VML Eqn Attribute

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Defines the equation used by a formula. Read/write. String.

Applies To

F (subelement of Formulas)

Tag Syntax

<v: element eqn=" expression ">

Script Syntax

element .eqn="expression"



Equations are defined by the evaluation of a text expression that has the general form of an operation followed by up to three arguments. Each argument may be of the following types:

  • adjustment (for example, #2)
  • another formula (for example, @2)
  • fixed numbers (for example, 2)
  • predefined values

The table below defines the formulas that can be used withthe optional arguments given the names v, p1, and p2.The formula pattern is:

<f eqn=" operation [v ] [p1 ] [p2 ]"/>

Operation Params Exact Result Description
val 1 yes v Defines a guide value from some other value.
sum 3 yes v + p1 - p2 Used for addition and subtraction.
product 3 rounds v * p1 / p2 Used for multiplication and division.
mid 2 (c) (v + p1)/ 2 Average.
abs 1 yes abs(v) Absolute value.
min 2 yes min(v,p1) The lesser value of v and p1.
max 2 yes max(v,p1) The greater value of v and p1.
if 3 yes v > 0 ? p1 : p2 Conditional testing.
mod 3 no sqrt(v^2 + p1^2 + p2^2) Modulus value.
atan2 2 no atan2(p1,v) Polar value in degrees * 2^16 (fd units).
sin 2 no v * sin(p1) Sin, argument in degrees * 2^16 (fd units ).
cos 2 no v * cos(p1) Cos, argument in degrees * 2^16 (fd units ).
cosatan2 3 no v * cos(atan2(p2,p1)) Preserves full accuracy in intermediate calculation.
sinatan2 3 no v * sin(atan2(p2,p1)) Preserves full accuracy in intermediate calculation.
sqrt 1 no sqrt(v) Result is positive and rounds down.
sumangle 3 yes v + p1 * 2^16 + p2*2^16 v scaled by 2^16; p1 and p2 are degrees.
ellipse 3 no p2 * sqrt(1-(v/p1)^2) Ellipse.
tan 2 no v * tan(p1) Tangent, argument in degrees * 2^16 (fd units ).

Note that the equation only consists of operations and numbers; mathematical symbols are omitted. For example, the equation

eqn="sum 5 9 3"

would yield the equivalent of

5 + 9 - 3

for the returned value of 11. If operands are missing, the value is not used. For example,

eqn="sum 5 9"

would yield the equivalent of

5 + 9

and would ignore the missing operand.

VML Standard Attribute


The following formula would yield a result of 6 (the sum of both numbers divided by 2), which, if this were the first formula, could be retrieved by the symbol "@0".

    <v:f eqn="mid 5 7"/>