#analysis Articles


Cartographica 1.5: Formula Changes

TL;DR - if you're using formulas, read the Practical Changes section. Background Although it's been called out in our documentation for years, many people don't realize that the underlying system behind Cartographica's calculated columns is actually a full Python interpreter. This has allowed us to provide a full-featured function/method interpretation system, with sophisticated math and date calculation capabilities without having to build and maintain such a thing ourselves. Along with the many internal changes in Cartographica 1.5, we are preparing for Apple's announced deprecation of the Python libraries in macOS by moving to using our own internal Python …

Introducing Cartographica 1.4: Cluster Analysis

Cartographica 1.4 now has the ability to perform Cluster Analysis. Cluster Analysis involves choosing and setting a number of parameters that are used to identify "hot spot" locations of point level data. Clusters are areas that have high concentrations of a particular incident. Knowing where high concentrations of certain things are located can be a very valuable tool for analysts conducting spatial analysis. The two main parameters used to identify clusters are Minimum Count and Distance. Minimum Count allows you to determine how many points are needed to identify a cluster. For example, if the minimum count is set …

Introducing Cartographica 1.4: Spatial Join

New to Cartographica 1.4 are the Spatial Join tools. Spatial Joins are used to combine the data attributes of two or more layers. The Spatial Join operation creates a new layer that is a combination of attributes from Join and Target layers. The Spatial Join functions are akin to the Overlay functions except that the Spatial Join procedure does not change the geometry of the layers. Spatial Joins can be used for many different purposes and there are many options for determining how the join will be processed. A Spatial Join can be performed on point, line, or polygon …

Introducing Cartographica 1.4: Overlay Operations

New to Cartographica 1.4 is the ability to perform Overlay Operations. Overlay Operations are useful in many contexts when working with spatial data as they make limiting or expanding datasets via spatial location simpler and more efficient. Below are descriptions of the various Overlay Operations that Cartographica has in place for version 1.4. Each serve a specific purpose that you may encounter while working with spatial data. Clip Function: Clips all target layers to the Clip layer. The Clip layer can be thought of as a cookie cutter. The boundary of the Clip layer is the outline of …

Introducing Cartographica 1.4: Snapping Functions

Cartographica has had the ability to add and create new features for a while now, but new in version 1.4 are the snapping tools, designed to make the Add Feature process simpler and more efficient. Snapping tools make it easier to draw point, line, and polygon features by automatically connecting to Vertex, Edge, or Grid features on a layer. That is, if your goal is to create a new layer, or to update an old layer, then using the snapping tools allows you to more easily draw the new features. We can illustrate with an example. In the following …

Introducing Cartographica 1.4: Layer Styles and the Uber Browser

The Layer Styles Window has been enhanced for version 1.4. The User Interface is similar, but includes several new or upgraded functions. New functions include additional editing capability on both lines and patterns for layer features, enhanced management of feature labels, new line and fill patterns, and integration with the Uber Browser. The new line and pattern styles have variable colors and can be used through drag and drop. Also new to version 1.4 is the Uber Browser, which is designed to enhance your ability to edit and improve your layer styles. The Uber Browser is a collection …

Negative Buffering in Cartographica

Buffers have many applications for users of GIS. A buffer is a polygon that is drawn at specified distances around a set of point, line, or polygon features. Buffers are often used to indicate the proximity of a feature to other surrounding features. For example, school officials in one community wanted to know which schools were within 500 yards of parks due to increased reports of students skipping school in those locations. There are different types of buffers, but the most common method is the Uniform Width Buffer. This method identifies areas that are specific distances from a set of …

Core Logic Report on Wind, Hail, and Tornado Risk

We have done a lot of posts about tornado activity in the past on this blog. This is largely due to the interesting data that are openly available as well as the awesome power that tornadoes contain, which naturally makes them interesting. The recent tornado activity in Indiana and Kentucky and then Monday's dramatic daytime tornado that ripped through through the Dallas area has again brought my attention back to tornadoes. Recently Core Logic produced an interesting study on tornado and hail damage throughout the United States. Get the article here The report looks at similar data that we have …

Mapping 2011 Washington D.C. Crime Data

Washington D.C. has an excellent catalog of GIS data that is made available to the public at DC GIS. The website provides data on all sorts of issues ranging from criminal activity to building permits. Also the website contains spatial files that can be used to create detailed and professional maps. For this post I collected data on 2011 crimes within the city. I will show how to import the data into Cartographica, how to geocode the crime incident data, how to search for specific types of crimes, and how to create Kernel Density Maps. The first step in …

Mapping Recent Earthquake Activity

Recently there have been several earthquakes around the world. In Negros-Cebu region, Philippines there was a 6.7 magnitude earthquake that resulted many injuries and deaths. The earthquake activity peaked my interest to explore what was happening around the world in terms of seismic activity. To find data on recent earthquake activity I went to the U.S. governments data portal Data.gov, which is a clearinghouse for thousands of maps and datasets. I found data on earthquakes for the past 7 days. The link to this data is here. When you go to the webpage you will see that …