Linear and nonlinear scales

One of the most common traits found on gauges are their characteristic scales, with tickmarks and matching numeric values.

In most design apps these scales have to be created by entering each tickmark value one by one. Even with convenient radial copy tools, this can still take some time, especially when trying different options.

GaugeMaster Pro takes advantage of some key patterns that characterize gauges and provides parametric tools to quickly generate tickmarks and value sequences with very little effort. These type of tools are mostly for linear gauge scales.

For more complex designs where tickmarks or values may not have a linear correlation between them, the app has a powerful nonlinear option. With this option you can import a CSV spreadsheet file to easily generate tickmarks and values at precise arbitrary locations across an arc.

Linear

Linear scales are usually made up of a segment that gets repeated for a number of major steps/divisions on the arc. For example, a pressure gauge from 0 to 100 bar may have a linear segment with one major tickmark and nine minor tickmarks, repeated every 10 bar.

Within every segment we can specify any combination of tickmarks by adding subsegments that define the following parameters for the tickmarks they represent:

• count: how many tickmarks to draw for the subsegment
• length: the tickmarks length within the width of the arc, from 0 to 1, 1 being the full arc width
• shape: the tick shape of the tickmarks on this subsegment, lines, dots, triangles or diamonds
• width: the thickness of line tickmarks on this subsegment, or the width ratio of triangles and diamonds

On the previous 1 to 100 bar example, we would have two subsegments, the one defining the major tickmark, and the one defining the 9 minor tickmarks as follows:

When editing any of the subsegments, its tickmarks will show in red on the segment preview at the top of the subsegment list, and on the gauge on the canvas. As you modify the subsegment values you will see them updating in real-time so you can quickly define your needed tickmarks pattern. A hidden subsegment shows in light grey on the preview, and in a lighter red on the canvas while it is selected.

Sample segment designs

You can select any of the sample tickmarks segment designs with the Sample Formats button, and look at them with the Scale Format editor button, to see how the subsegments are used to create the sample designs. The sample designs offered depend on the canvas Industry selection.

The Scale Format editor button will always display the current tickmarks segment design.

The closing tickmark

If you count the tickmarks on the Sample Format editor button, you will notice there is one last extra tickmark that is not defined by any of the subsegment items. This last tickmark is a copy of the first tickmark on the first subsegment, as this is usually how almost all gauges close their tickmark scales.

On some gauges this is not the desired pattern, so there is a Draw Final Tick option that can be disabled.

Be aware that disabling the Draw Final Tick will make the last tickmark of the last subsegment be the last tickmark on the arc, causing all other tickmarks to be spaced accordingly to fill the entire arc length.

Nonlinear

Nonlinear scales allow full freedom to design your scales. They are built from CSV files you generate on your favorite spreadsheet app. The CSV file will contain the location of the nonlinear element (tick mark or text), and any other key details required to render it, as specified below.

The format of each line on this CSV file is as follows:

Tickmarks Arc

• location: location within the arc, being 0 the start angle and 1 the end angle.
• length: length of the tickmark within the width of the arc, being 1 the full width of the arc.
• width: the thickness of the tickmark.

Text Arc

• location: location within the arc, being 0 the start angle and 1 the end angle.
• text: the text for each location.

Here are some sample nonlinear tickmarks arc spreadsheet values:

location	length	width
0	1	3
0.053	0.5	2
0.158	1	3
0.394	1	3
0.655	1	3
0.827	0.5	2
1	1	3

And here is the resulting nonlinear tickmarks arc CSV file content:

location,length,width
0,1,3
0.053,0.5,2
0.158,1,3
0.394,1,3
0.655,1,3
0.827,0.5,2
1,1,1

Here are some sample nonlinear text arc spreadsheet values:

location	text
0	0
0.16	2
0.39	5
0.66	8
1	10

And here is the resulting nonlinear text arc CSV file content:

location,text
0,0
0.16,2
0.39,5
0.66,8
1,10

Header line on CSV file

The header line is required on these CSV files when importing them into the app.

And here is the resulting gauge with the tickmarks and text arcs:

Nonlinear CSV files

Nonlinear tickmarks and text arc CSV files have different formats, as shown above, and to be imported correctly each file must have the correct format.

Importing/Exporting CSV files

Use the Import nonlinear CSV file button to load the CSV file for your nonlinear arc.

You can also use the Export nonlinear CSV button to export the CSV file of any existing nonlinear arc. This could be useful to restore the CSV file of an old gauge design or to tweak some of the values of nonlinear arc.

Check the nonlinear sample gauge

The Refrigeration sample gauge is a very good example of a nonlinear gauge. You can export any of its tickmarks or text nonlinear CSV files to learn how they are used.

Editing individual items

Since nonlinear arcs are created with individual elements at precise locations determined by you, you edit these details individually with the nonlinear editor.

Use the Scale Format editor button, the tickmarks preview button, to access the nonlinear tickmarks arc editor list.

Use the Edit Nonlinear Text button to access the nonlinear text arc editor list.

This will provide a list with each individual tickmark or text entry, where you can reposition or adjust its other settings, including each item’s visibility. Tickmarks imported from a CSV file always come in as lines, so the tick shape of each one is set on the list, with the Set All: buttons setting one shape onto all of them at once.

Copy to Nonlinear

Sometimes a gauge may contain arcs that are mostly linear in design, but that due to some specific requirements would need to be handled as nonlinear.

In some of those cases it may be possible to initially design the arc as linear, and then use the Copy to Nonlinear button to complete the editing in nonlinear mode. Tickmarks keep their tick shapes on the copy, and any numerical scales copy their values as editable text items, including Roman numerals.

Tick Shapes

Tickmarks are not limited to lines. Every subsegment of a tickmarks scale, linear or nonlinear, can have its own shape, chosen with the Shape selector on its row of the Scale Format list:

• Lines, the classic tick.
• Dots, a circle whose diameter is its Length.
• Triangles In, with the tip pointing to the gauge center.
• Triangles Out, with the tip pointing outward, the bezel and tachymeter convention.
• Diamonds.

New subsegments start as Lines, and a subsegment added while another is selected copies that one’s shape.

The row’s size fields are specific to each shape type. Length always applies, as the radial size of the shape as a fraction of the arc width. Width, in the current measurement unit, shows only for Lines. Width Ratio shows only for triangles and diamonds and sets the shape’s tangential width as a ratio of its radial size, from 0.05 to 2, so 1 is as wide as it is tall. Dots have no width field.

The Copy to Nonlinear button carries each subsegment’s shape and its details across to the nonlinear scale, and the layer’s Width Scale and Alignment settings apply to every shape.

Existing files open unchanged

Files saved before tick shapes were available open with every subsegment as a Lines subsegment with its saved width. The nonlinear CSV import and export format is unchanged too.

Set All

The list header has a row of Set All: buttons, one per shape, where each sets that shape onto every subsegment of the scale at once, for quick changes. Handy as well after importing a nonlinear CSV file, whose tickmarks always come in as Lines.

Hiding Subsegments

The Scale Format list items, linear and nonlinear, have a visibility toggle, the eye button under the row number. A hidden subsegment is not drawn on the canvas or in prints and exports, but it keeps its slot, its guides and its snapping, so it can be switched back on without disturbing the scale. Hidden subsegments show in a light grey in the scale preview.

While editing the list, the selected subsegment’s tickmarks are highlighted in red on the canvas, or in a lighter red when that subsegment is hidden, so it can still be seen. The highlight is an editing aid only and never appears in prints or exports.

The Edit Nonlinear Text list of a nonlinear Text Arc layer has the same visibility toggle for its text items.