Logarithmic marks left/right/top/bottom...

Four of the commands in the Margins menu of the Picture window.

## Purpose

To draw a specified number of marks per decade into the margins around the drawing area, along a logarithmic axis.

## Settings

Marks per decade
  the number of marks that will be drawn for every decade.
Write numbers
  if on, real numbers will be written in the margin, expressed in the domain or range of your latest drawing in the horizontal or vertical direction.
Draw ticks
  if on, short line pieces will be drawn in the margin.
Draw dotted lines
  if on, dotted lines will be drawn through your drawing.

## Behaviour

  If your vertical logarithmic axis runs from 10 to 100, and Marks per decade is 1, marks will only be drawn at 10 and 100;
  if Marks per decade is 2, marks will be drawn at 10, 30, and 100;
  if it is 3, marks will be drawn at 10, 20, 50, and 100;
  if it is 4, marks will be drawn at 10, 20, 30, 50, and 100;
  if it is 5, marks will be drawn at 10, 20, 30, 50, 70, and 100;
  if it is 6, marks will be drawn at 10, 15, 20, 30, 50, 70, and 100;
  if it is 7 (the maximum), marks will be drawn at 10, 15, 20, 30, 40, 50, 70, and 100.