You can combine MM-Talk functions as required to create longer formulas. You can also make several variable assignments in a formula; the individual assignments must then be separated from each other by semicolons.
$Variable1 :=Expression1;
...
$Variables :=Expressionn;
Result expression
The variable assignment must be at the beginning of the formula. Once a variable has been assigned, it can be used as often as required in any expression of a formula.
The following example, in which a formula is created to calculate a price difference from the previous day, shows you step by step how to create a complex formula:
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The input object is a security. First, the current close time series is queried and stored in the variable "$Close":
$Close:=Close;
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The same procedure is used for the close time series from the previous day; the result is assigned to the variable "$Close1".
$Close1:=$Close.Before[1];
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Finally, the difference between the two time series is calculated. The result is also a time series:
$Close-$Close1
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The finished formula is:
$Close:=Close; $Close1:=$Close.Before[1]; $Close-$Close1
By using the variables cleverly, you save one access to the close time series for each call of the formula in this example.