Graph and Chart Manager

Introduction

Global Mapper can produce various types of charts and graphs, for example:

Once a user has defined a graph, Global Mapper stores the definition in the workspace associated with the data. The graph or chart can be embedded in a map so that it can be printed.

Graph and Chart Manager

The Graph and Chart Manager (below) allows the user to set up a new graph, and to see a list of the graphs defined in the current workspace. To display this window, select the Graph and Chart Manager... option on the Analysis menu.

Using the Graph and Chart Manager, a user can perform following functions:


The Graph and Chart Manager window contains the following UI elements and data:

List Contains the title and data layer for each graph in the current workspace. Click on an entry in the list to select it. Only one entry can be selected at a time.

New... Click this button to open the Graph Properties window to define a new graph.
Open... Click this button to displays the selected graph in the Graph window. This button will be disabled until the user selects a graph in the list.
Delete Click the Delete button to remove the selected graph from the list and from the current workspace. This button will be disabled until the user selects a graph in the list.
Properties... Click this button to open the Graph Properties window initialized with information from the selected graph definition so that it can be edited. This button will be disabled until the user selects a graph in the list.
Close Click this button to close the Graph and Chart Manager window.

Graph Properties Window

The Graph Properties Window displays the map information and options associated with a graph definition, and a preview of the graph. This window can be used to create a new graph and edit an existing graph definition. As the user changes options (data layer, attributes, style, etc.) the preview will be updated.



The Graph Properties window contains the following elements:

Properties

The Properties Section contains information used to define the graph:

General - Options that apply to the graph as a whole

Data Series - Options that apply to the graph data

The Preview Section displays the graph or chart, and gets updated in real time as the user changes the definition.

General Tab

When the user clicks on the tab marked "General", the following screen will be displayed:



The General Tab contains the following information that applies to the graph as a whole:

Title - This is the main title for the graph, and is used to identify the graph on the Graph and Chart Manager screen. Type the graph title in the associated textbox. As the data is typed into the box, the graph preview will be updated to reflect the change.

Show Legend - Put a check in this box to add a legend to the graph. When the box is clicked, the graph preview will be updated to show or hide the legend, depending on whether the box is checked or unchecked, respectively. Use the Data Series tab to specify the contents of the legend.

Vertical Alignment - Choose an option from this list to specify the vertical component of the legend's location. The legend can be:

Horizontal Alignment - Choose an option from this list to specify the horizontal component of the legend's location. The legend can be:

When the user makes a selection, the legend on the preview will be moved to reflect the choice.

Data Series Tab

This tab contains the definition of the type of graph and data to be used. Global Mapper can create the following types of graphs:

Histogram

Global Mapper can create a histogram from a Lidar data set, an attribute associated with a vector layer, or an elevation grid. When the input data is a Lidar data set or vector layer, Global Mapper will count the instances of each value associated with the attribute being graphed, then group those values into bins. Each bin will be a bar in the graph. If the value data is character data instead of numeric, then the graph will contain a bar for each value.

When the data is an elevation layer, the elevation values will be grouped into bins, and each bin will be a bar in the graph.

Bar Chart

A bar graph can be created from attribute data in a vector layer or a Lidar data set. The data values in the attribute will be summed up based on the category attribute. The X-axis will show the categories, and the height of the bar represents the sum for each category.

Bar Chart - Horizontal

A horizontal bar graph is similar to a bar graph except that the Y-axis shows the categories and the length of the bar represents the sum for each category.

Pie Chart

Global Mapper can create a pie chart from attribute data in a vector layer or a Lidar data set. The data values in the attribute will be summed up based on the category attribute. The size of each pie section will represent the percentage of the total for the associated category.

Click the Data Series tab to display the following window:


The Data Series tab contains the following that applies to the data in the graph:

Type of Graph - Select the type of graph to be created from the following list:

When a choice is made, the preview will be updated to reflect that choice.

Source Layer Name - Choose the data layer that will be used to generate the graph. The list will contain only layers that are suitable for the currently selected graph type. If the type is Histogram, then elevation layers, Lidar layers, and vector layers will be in the list. For all other graph types, the list will contain only Lidar data sets and vector layers. When a choice is made, the preview will be updated to reflect that choice.

Value Attribute - Choose the attribute used to provide values for the graph. If the user has selected an elevation layer for the source layer, then this list will be disabled. When a choice is made, the preview will be updated to reflect that choice.

Value attribute contains numeric data - Put a check in this box if the data in the value attribute is numeric. This box will only be enabled when the graph type is Histogram. In all other cases, the value attribute must contain numeric data, so this item will be checked and disabled.

X Point Label Attribute - Choose the vector layer attribute that will provide the X-axis label for the graph. This attribute value will also be used to group multiple features into a single bar or pie section. If the user has selected an elevation layer for the source layer, then this list will be disabled. When a choice is made, the preview will be updated to reflect that choice.

Data Labels section - Contains options related to the labels that will be attached to the graph data.

Show labels on graph data elements - Check the box to enable the data labels to be displayed. This item will be disabled until the user has selected the graph type and data layer. The preview will be updated when this option is clicked.

Label Contents - Choose an option that determines what data will be included in the label. Choices are:

Attribute refers to the value associated with the attribute in the X Point Label Attribute field. Value refers to the number used to determine the length of the bar, size of the pie section, etc. This item will be disabled when the check box used to show labels is not checked. When a choice is made, the preview will be updated to reflect that choice.

Number of Bins - Type in the number of bins to be used in a Histogram. If the graph type is anything other than Histogram, this field will be disabled. The preview will be updated when a value has been entered and the user releases focus from this field by tabbing to or clicking on another field.

X-Axis Name - Type the name to be displayed along the X-axis. The preview will be updated as the data is typed in.

Y-Axis Name - Type the name to be displayed along the Y-axis. The preview will be updated as the data is typed in.

Legend Title - Type the title to be used for this data series in the legend. The preview will be updated as the title is typed in.

Color section - Use the radio buttons in this section to choose the color scheme for the graph.

Use default color - Check this radio button to allow Global Mapper to choose the color for the data series. The preview will be updated when this selection is made.

Match color to associated feature - Check this radio button to match the color of each graph element to its associated feature. This option will be disabled if the graph type is Histogram. The preview will be updated when this selection is made.

Use custom color - Check this radio button to choose a color to be used for the data series. The preview will be updated when this selection is made.

Select... - Click this button to display a color selection dialog. Once the selection has been made, the rectangle to the left of the button will be updated with the selected color, and the preview will also be updated.

Advanced - Choose Horizontal angle for graph text and the number of digits right of decimal for numeric values.

Graph Window

The Graph Preview window contains the graph and some controls that allow the user to work with the graph.


The Graph window contains the following UI elements and data:

Graph - The largest area of the window contains the graph itself.

Save BMP Display on Map... - The user selects the location where the BMP file will be stored, and specifies where it should be located on the map and how large the image should be.

Cancel - Closes the Graph window.

Pixel Information

When the Feature Info Toolis used to select a pixel, a Pixel Information dialog displays the following information in a either a line or bar graph:

Graph of band values



Layer - This field contains the description of the layer that contains the pixel.

Location - Displays the coordinates of the pixel in the global projection.

Row, Column contains the pixel location within the raster image. If the raster is an elevation grid, there is also an Elevation field that contains the elevation, slope, and slope direction at the selected pixel.

Graph Type - This field allows the user to choose to display the graph as a bar graph or line graph.

Bands - This section contains a list of the values for each band in the pixel. The bands designated as red, green, and blue will be labeled as such, and the other bands will be labeled as “Band n”. If the user clicks on one of the lines in the Bands list, the corresponding graph bar or point will be highlighted.

Graph - This section contains the graph itself, and the Show point labels check box, which permits the user to show or hide the labels that are above each bar or point in the graph. If the graph contains a large number of points, the user has the option of narrowing the view area to a portion of the graph, and scrolling to see the rest. This is controlled using the Fit data to graph window check box.

When the box is checked, all of the data will be displayed in the graph window (the number of labels will be adjusted to make them readable.) When the box is not checked, the view will contain a portion of the graph, and the user will be able to scroll left and right to see the rest. In this case, all of the labels will be displayed. See the screen captures below for an example of the difference: