Tip 16. Users units of physical values

Fig. 16. Users units of physical values

There are predefined variables in Mathcad, which keep built-in units of physical values in different systems (see the sketch Mathcad and physical values (http://twt.mpei.ac.ru/ochkov/Units/unit.htm), as well as one of the books of the given series Physical values in Mathcad). But user has the right to extend this list and to introduce into calculation user's units (see fig. 16), which are connected with built-in ones via corresponding coefficients[1].

At the beginning of a calculation user is not able to know what new units will be necessary. They can be introduced into the calculation as required: for example, it is necessary to output time in weeks it is enough to come back to beginning of the calculation and to write week:=7 day and etc.

(exactly like this: 7 day, but not 7day see tip 9).

The operator  := m is handily in one more case. It is possible to fall into a reverie and to assign the variable m (but it is very popular) some new value (see tip 1) in a calculation. This operation is able to break all harmonious system of physical values laid in Mathcad. But the operator  := m releases the variable m for keeping something else.

We could find the continuation of the theme in the sketch Mathcad and physical values (http://twt.mpei.ac.ru/ochkov/Units/unit.htm).



[1] How to work with degree Celsius, which can not be introduced via the conversion factor in a calculation see tip 64.