The Calcpad language

The sheet format is a front end. Underneath, every sheet becomes a Calcpad worksheet, the language of CalcpadCE, and the engine runs that. You can also write Calcpad directly: choose File > New Calcpad worksheet (the second item of the File menu, also on the Resources tab), or open a .cpd file.

Use the Calcpad language when you need something a sheet does not offer on its own: macros that repeat a block with different arguments, input forms with drop-downs and grids, output control (hide a block, show only results), the numerical commands, reading and writing data files, or when you are working with worksheets from the CalcpadCE community.

How a Calcpad worksheet reads

A worksheet is a list of lines. Each line is one of these.

First character	Kind	Example
`"`	Heading, a comment shown as a heading	`"Beam check`
`'`	Text, a comment shown as written (HTML allowed)	`'Span -'L = 6m`
`#`	A directive	`#if`, `#for`, `#def`, `#hide`
`$`	A command	`$Plot{x^2 @ x = 0 : 5}`
anything else	A calculation	`M = wL^2/8\|kNm`

A single quote also switches between text and calculation inside a line, which is how labels sit in front of an equation: 'Span -'L = 6m shows the text “Span -” and then the equation.

"Beam check
'Span -'L = 6m
'Load -'w = 12kN/m
'Moment -'M = w*L^2/8|kN*m
#if M < 100kN*m
    'OK
#else
    'Too large
#end if

Beam check
Span - L = 6 m
Load - w = 12 kN/m
Moment - M = w·L²/8 = 12 kN/m · (6 m)² / 8 = 54 kN·m
OK

Sheet and Calcpad side by side

Sheet	Calcpad
`L: 6 m \| span`	`L = 6m 'span`
`M: wL^2/8 -> kNm`	`M = wL^2/8\|kNm`
`# Heading`	`'<h1>Heading</h1>`
`Plain paragraph`	`'Plain paragraph`
`if u <= 1: "OK" else: "Fails"`	`#if u ≤ 1` … `#else` … `#end if`
`for i in 1..5:` + indented body	`#for i = 1 : 5` … `#loop`
`f(x, y): x + y`	`f(x; y) = x + y`
`[1, 2; 3, 4]`	`[1; 2 \| 3; 4]`
`plot f(x) for x in 0..5`	`$Plot{f(x) @ x = 0 : 5}`
`phi`, `Mstar`	`φ`, `M_star`

Function arguments are separated with ; in Calcpad, matrix rows with |, and a unit conversion is a vertical bar. A sheet writes commas, -> and brackets, and the compiler does the translation. To see it for any sheet, use Show compiled.

Operators

^ power, * multiplication, / division, \ integer division, ⦼ modulo (type %%), ! factorial, + - , comparisons ≡ ≠ < > ≤ ≥ (type == != <= >=), logical ∧ ∨ ⊕ (type && || ), = assignment, ← assignment to an outer scope. The editor converts the typed forms when you open a file. The complete table is in the reference.

Angles

Angles are in degrees unless you say otherwise. #rad switches the rest of the worksheet to radians, #gra to gradians and #deg back. This matters whenever you pass π or a plain number to a trigonometric function. See Troubleshooting.

Output control

Directives shape what the report shows without changing the calculation.

#hide
k = 3
#show
a = k*2
#val
b = k*3
#equ
#nosub
c = k*4
#varsub

a = k·2 = 3 · 2 = 6
9
c = k·4 = 12

#hide … #show calculates but does not print, #val prints only the value, #nosub prints the formula without the numbers put in, #noc the formula without the result and #novar only the substituted numbers. #pre and #post split a document into the part that is filled in on screen and the part that appears in the report. The complete list is in Directives.

What the next pages cover

Directives and commands: conditions, loops, macros, modules, constants, settings, files, numerical commands.
Input forms with #UI: the #UI directive, grids and entry options.
Templates with inputs: fill-in forms, and the ? input lines of a sheet.

Related pages: Calcpad worksheets in the browser. More pages are in Calculators and guides.

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