# Label display function¶

Label display function is the function to visualize calculation result values defined at grid nodes, cells, edges etc. as string on visualization windows.

You can use the function on [2D Post-processing Window] and [3D Post-processing Window].

You can define the label with the following steps:

1. Add [Calculation results for input]
2. Define [Definition of output]
3. Edit settings of position, size, fonts etc.

Please refer to next sections for detail.

## Add [Calculation results for input]¶

When you click on [Add] or  button in [Calculation results for input] group box, the dialog in Figure 458 is shown, and you can add or edit calculation results for input of labels.

The details of each item on the dialog is described in Table 41.

Table 41 [Edit String Result Argument] dialog items
Item name Description
Position The position where the calculation result is defined. You can select from [Global], [Node], etc.
Result Name The name of calculation result. You can select from combo box.
Variable Name The name to refer to this value, to use in [Definition of output].
I, J, K, Index Enabled when [Position] is not [Global]. You can use these to select the grid node (or cells etc.)
Value for testing When user click on “Test” button on [Label Setting] dialog, value defined here is input to the variable.

## [Definition of output]¶

Please describe how to generate the label string, in [Definition of output]. You can describe by JavaScript language. Please refer to Examples of [Definition of output] for example.

Please use the [Variable Name] you’ve input in [Edit String Result Argument] dialog, to define label strings.

When you click on [Test] button, from the [Value for testing] for each variable, and from [Definition of output], the label string is generated, and displayed. If there are problems in the definition in [Definition of output], error meesage is shown.

In [Definition of output], you should input the definition, that return string at last.

## Edit settings of position, size, fonts etc.¶

You can edit settings of position, size, fonts etc. using the widgets in [Position and Size] group box and [Font and Color] group box.

You can also edit the position and size by dragging the label on visualization windows, when [Label] is selected in the [Object Browser].

## Examples of [Definition of output]¶

Basic informations and examples of [Definition of output] is described here.

### Newline character¶

When you want to output multiple lines as labels, you can use “\n” as Newline character. List 7 shows an example of definition that uses Newline character, and List 8 shows the example of output.

List 7 Example of [Definition of output] (Newline character usage)
var line1 = "This is the label at first line";
var line2 = "This is the label at second line";
return line1 + "\n" + line2;

List 8 Example of output (Newline character usage)
This is the label at first line
This is the label at second line


### Output numerical values specifying format¶

When you want to output numerical values specifying format, you can use the following functions.

• Fixed-point notation: toFixed()
• Exponential notation: toExponential()

With both functions, you can give decimal places as the argument.

List 9 and List 10 shows the example of Definition that uses toFixed() and the output. List 11 and List 12 shows the example of Definition that uses toExponential() and the output. With both examples, Discharge should be defined as variable name in [Calculation results for input].

List 9 Example of [Definition of output] (toFixed usage)
return "Discharge: " + Discharge.toFixed(3);

List 10 Example of output (toFixed usage)
Discharge: 23.321

List 11 Example of [Definition of output (toExponential usage)
return "Discharge: " + Discharge.toExponential(3);

List 12 Example of output (toExponential usage)
Discharge: 2.332e+1


### Output with control syntaxes¶

JavaScript language has control syntaxes, like if statement, for statement etc. You can use these syntaxes to define the [Definition of output].

List 13 and List 14 shows the example of Definition that uses if statement and the output.

List 13 Example of [Definition of output] (if statement usage)
var title = "Flood simulation";
var wl = "Normal";
if (Discharge > 2000) {
wl = "Over Limit";
}
return title + "\n" + "Discharge: " + Discharge.toFixed(3) + " (" + wl + ")";

List 14 Example of output (if statement usage)
Flood simulation
Discharge: 23.321 (Normal)