Number formats and value ranges

CGRAPH expects numerical values to be entered in many input fields. The formats and possible value ranges for such entries are explained below.

CGRAPH enters a default value in each input field. When you first start the programme, these are predefined values, but any changes to these values are saved as soon as a graph is created. The last values entered are then displayed the next time the graph is called up.

Right-clicking in an input field for real or complex numbers also displays a context menu that shows a series of predefined numbers (e.g. pi, 2*pi, …) as well as your last 5 entries, separated into real and complex numbers. This makes it much easier to change these values.

Integer numbers consist of a sequence of digits without a decimal point. Many input fields in CGRAPH limit the value range to a small interval; sometimes, for the sake of simplicity, a slider is provided instead of a number input. If free input is possible, the value ranges appear as a floating window when the mouse is moved over the input field.

Real numbers consist of the integer part, a decimal separator, the fractional part and a mantissa. Their value range is between -10¹⁰⁰⁰ and +10¹⁰⁰⁰; a full stop or comma can be used as the decimal separator, and “E” can be used as the mantissa sign. Correct numbers are, for example

Instead of numerical values, complete formulas can also be entered. These must be structured according to the CGRAPH function syntax, but may not contain any variables or parameters. The decimal separator is the character set system-wide on the computer, usually a comma or a point.

Complex numbers consist of a real part followed by an imaginary part, which are represented in the same way as real numbers. The imaginary part is indicated by the imaginary unit i or j. Purely real or purely imaginary numbers can also be entered. Correct numbers are, for example

Instead of numerical values, complete formulas can also be entered. These must be structured according to the CGRAPH function syntax, but may not contain any variables or parameters. The decimal separator is the character set system-wide on the computer, usually a comma or a full stop.

For entering two coordinates, CGRAPH defines real number pairs consisting of an opening bracket, a real number, a colon as a separator, a second real number and a closing bracket. The brackets can be omitted when entering the numbers. Correct numbers are therefore

Instead of numerical values, complete formulas can also be entered. These must be structured according to the CGRAPH function syntax, but may not contain any variables or parameters. The decimal separator is the character set system-wide on the computer, usually a comma or a full stop.

Real number triples are an extension of real number pairs, in which a third real number is additionally interpreted as the z-coordinate. Here, too, the colon is used as the separator. Correct numbers here are

Instead of numerical values, complete formulas can also be entered. These must be structured according to the CGRAPH function syntax, but may not contain any variables or parameters. The decimal separator used is the character set system-wide on the computer, usually a comma or a full stop.

Angles are entered in CGRAPH in degrees. The numerical values correspond to the format of real numbers; to indicate the degree format, the symbol ° is always appended to the output. It is not necessary to include this when entering values.

CGRAPH recognises various constants that are automatically converted into numerical values when entered

(The less common term ‘tau’ is used here for the golden ratio because the more familiar term ‘phi’ is already defined as a variable name for angles.

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