Engineering functions in Grid: units, bases and complex numbers

The engineering family sounds specialist, and parts of it are. But a few of its 54 functions are useful to almost anyone, starting with unit conversion. Grid by Zaweba includes the full set: number base conversions, bit operations, CONVERT with its unit table, the error function, Bessel functions and a family for complex numbers.

Converting units with CONVERT

CONVERT takes a number, the unit it's in and the unit you want, and returns the converted value. Miles to kilometres, pounds to kilograms, Fahrenheit to Celsius, gallons to litres: the unit table covers the everyday measures and plenty of scientific ones. A recipe scaled for a different kitchen, a running log in both miles and kilometres, or a parts list that mixes imperial and metric all become a single column of formulas.

Unit codes are short text such as "mi" and "km", and they have to match the table exactly. Insert Function lists CONVERT with its description and arguments, which is the place to check before you guess. If the units can't be converted into each other, CONVERT returns an error rather than a wrong number, which is the behaviour you want.

Keep the unit codes in their own cells and refer to them. Then a sheet can switch from metric to imperial by changing two cells at the top rather than editing every formula.

Number bases and bits

BIN2DEC and its siblings convert between binary, octal, decimal and hexadecimal. They're the everyday tools for anyone reading register values, colour codes, network masks or electronics data sheets. The BIT functions perform bitwise AND, OR and exclusive OR, and shift bits left or right, so you can test or set individual flags in a status value without leaving the sheet.

For general bases beyond these, the maths family's BASE function writes a number in any base, and the pair together cover most conversion jobs.

ERF and Bessel functions

ERF, the error function, turns up in statistics, heat flow and diffusion problems. The Bessel functions appear in vibration, waves and signal work. If you need them you'll know it, and it's handy to have them in a spreadsheet alongside your data and charts rather than in a separate maths package.

Complex numbers

The IM functions work with complex numbers written as text, such as "3+4i". There are functions to build a complex number from its parts, to take the real or imaginary part, to find its size and angle, and to add, subtract, multiply and divide, along with powers, roots, logarithms and trigonometry. Electrical engineers use them for impedance and AC circuit sums; students use them for coursework.

Because complex numbers are stored as text, ordinary arithmetic won't work on them. Always use the IM versions, and keep the real and imaginary parts in separate columns when you want to chart or sort by them.

A tidy engineering sheet

Put inputs at the top with their units in the label, keep constants in named cells using Define Name, and use CONVERT at the edges of the sheet so the core calculation works in one consistent system. A scatter chart of results against an input is a quick way to check that a formula behaves sensibly across its range.

Engineering functions in Grid by Zaweba sit beside the other 400 or so functions, so a single workbook can hold measurements, conversions, statistics and charts together, offline and on your own PC.