SolarOS 4.6.8 manual · app

calc

Scientific calculator and function plotter. On a graphical display, calc opens an expression list beside a Cartesian plot. From UART, USB CDC, Telnet, or any other text-only shell, the same command opens a scientific REPL without the plot pane. calc --text forces that REPL even when graphics are available.

The expression engine supports +, -, *, /, %, powers with ^, parentheses, scientific notation, and implicit multiplication such as 2pi or 2(x + 1). Built-ins include sin, cos, tan, their inverse functions, sqrt, abs, exp, ln, log, floor, ceil, round, min, max, pow, and atan2. Trigonometric input is in radians; rad(degrees) and deg(radians) convert explicitly. Constants are pi and e.

Rows can hold scalar calculations, variables, one-argument functions, or plots:

a = 2
f(x) = sin(x) / x
f(pi / a)
y = f(x)

For a one-off shell calculation, use:

calc -e "sqrt(2)^2"

Text REPL commands:

• :list or :vars shows worksheet rows and scalar results.
• :del N removes a row; :clear empties the worksheet.
• :save [file] and :load [file] write or restore one expression per line.

The default file is calc.txt in the current shell directory.

• :help shows the compact reference; :quit returns to the shell.
• Up/Down recalls input history; Left/Right, Home, End, Backspace, and Delete

edit the current line.

Graphical controls:

• The expression editor keeps a white background for legible small text and

outlines the active row with a thin dark border.

• Type to edit the selected row; Up/Down changes rows and Enter adds a row.
• Left/Right, Home, End, Backspace, and Delete edit within a row.
• Page Up toggles the selected graph row.
• Tab moves between the expression list and graph.
• In the graph, arrows pan, +/- zoom, and Home or 0 resets the view.

Press t for a numeric trace cursor; Left/Right moves it and Up/Down selects another plotted row. Press t again to resume panning.

• Ctrl+S saves and Ctrl+O loads the default calc.txt worksheet.
• App-exit closes the calculator. The worksheet is kept only when explicitly

saved.