EQDEF: Difference between revisions
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<code>@label@ { [[options]] } EQDEF [*] [[expression]]</code> | <code>@label@ { [[options]] } EQDEF [*] [[expression]]</code> | ||
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Define an equation. The [[expression]] must be of the form <code>expression1 = expression2</code>. | Define an equation. The [[expression]] must be of the form <code>expression1 = expression2</code>. | ||
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For the special case of the equation label starting with <code>lib:</code>, the equation will not be erased by <code>[[CLEAREQUATIONS]]</code>. This is useful for building a library of generic equations. | For the special case of the equation label starting with <code>lib:</code>, the equation will not be erased by <code>[[CLEAREQUATIONS]]</code>. This is useful for building a library of generic equations. | ||
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<code>@y@ EQDEF y = 3 x + 4</code> creates the equation and stores it for later usage under the label <code>@y@</code>. iMath also remembers that the numeric value of <code>y</code> can be found from this equation provided that <code>x</code> is given a numeric value in some other equation. | <code>@y@ EQDEF y = 3 x + 4</code> creates the equation and stores it for later usage under the label <code>@y@</code>. iMath also remembers that the numeric value of <code>y</code> can be found from this equation provided that <code>x</code> is given a numeric value in some other equation. | ||
Revision as of 09:12, 25 March 2017
Syntax
@label@ { options } EQDEF [*] expression
Implemented in iMath since version 2.2.0 or earlier.
Explanation
Define an equation. The expression must be of the form expression1 = expression2.
The starred form will suppress printing of the result.
For the special case of the equation label starting with lib:, the equation will not be erased by CLEAREQUATIONS. This is useful for building a library of generic equations.
Example
@y@ EQDEF y = 3 x + 4 creates the equation and stores it for later usage under the label @y@. iMath also remembers that the numeric value of y can be found from this equation provided that x is given a numeric value in some other equation.
@lib:pythagoras@ EQDEF c^2 = a^2 + b^2 creates the equation and stores it permanently. It can then be used by substituting values for a and b into it and solving for c.
See also
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