|Get on the Grid: A look at the powerful grid coloring capabilities in MapInfo Pro Advanced
||MapInfo Pro Advanced is a new raster grid visualisation and analysis add-on for MapInfo Pro. The first release is currently available on an extended preview basis.
Before we get started, there is some background info available which you may find helpful. In previous issues we have provided an article on the background concepts to grid mapping, as well as a brief overview of MapInfo Pro Advanced.
|Need an overview of some of the concepts behind raster grid mapping?
|Want to see an overview of what is in MapInfo Pro Advanced?
|Would you like to try installing and using MapInfo Pro Advanced yourself?
Scope of this article:
This article will focus on the grid coloring. In the examples below the Sunshading and Highlight features are being used. We will cover these capabilities in more detail in a future article.
Grid Coloring part 1: Choosing a color table for your grid
In the Raster tab, the Display group includes a gallery of color tables to choose from for your grid. A color table is a sequence of colors that are applied from the lowest to the highest value of your data. (More on that later.)
One thing you definitely need to experiment with is to mouse over the list of color tables – notice that as you do this, the grid display changes dynamically. Just click when you have found the color table you want.
Here are four examples of the color tables. You have more than 60 to choose from. A wide variety of color tables are provided for rendering different types of data.
Four examples of color tables.
Grid Coloring part 2: Choosing the Color Stretch option
As mentioned above, the color table is a sequence of colors. The color stretch capability provides different methods of assigning how the colours are spread through the data.
As with the color tables, you can mouse over these different options to see the impact of the choices on how your data is visualised. The grid will preview the option interactively and nearly instantly. This can be done, even with very large grid files.
Here is some information on the different Color Stretch methods.
The colors are evenly distributed in a linear mode between the minimum and maximum values of the data. The clip options mean that grid cells below the low value or higher than the top value will not be displayed. This might be helpful in removing outliers from your data.
The colors are distributed in an equal area mode between the data minimum and maximum. This means each color is represented by approximately the same area of data (or takes up the same amount of area on the map).
The color breaks are set around the mean of the data to two standard deviations both above and below the mean.
The colors are distributed according to natural clustering in the data distribution
The colors are distributed according to percentile range between the minimum and maximum
Fully customised color intervals are supported via the Advanced Color Options (see next).
Grid Colouring part 3: Advanced options
Many users might find the built in tables and color stretch options provide good visualisation. However, I would encourage you to look at the Advanced Options too. There are some powerful capabilities here.
Grid Coloring part 4: Analysing your data by setting dynamic breaks
The Color panel provides the ability to set custom color breaks for your data. You can do this interactively and with very large grids. The implication of this is that it becomes an analytical visualisation tool.
Adjusting the bin count
In the example above, the initial bin count was too high to show much of a representation in the histogram. Reducing the bin count increases the number of cells within a bin and as a result, the height (of the Y axis values) taken by the histogram.
The histogram on the left used the default Bin Count. This bin count was reduced in the histogram on the right. This helps to increase the scale of the Y axis of the graph.
Moving the Color Breaks
A “before and after” example of moving the color breaks appears below.
In the map on the right, some of the color breaks have been moved.
Want to try MapInfo Pro Advanced?
The free trial is available here: http://web.pb.com/miprov15-2
In case you are wondering, that is the free trial for the latest version of MapInfo Pro. The free trial includes the Advanced capabilities.
Article by Tom Probert, Editor of "The MapInfo Professional" journal
When not writing articles for "The MapInfo Professional", Tom enjoys talking to MapInfo Professional users at conferences and events. When not working he likes to see movies with car chases, explosions and kung-fu fighting.