Choropleth map

Abstract: In the transition from traditional forms of mapping to computer-assisted techniques, many manual tasks were converted directly into automated procedures. Focusing on the form of the final map product, cartographers developed totally distinct algorithms for the display of choroplethic and isarithmic maps. However, both types of maps can be stored as a digital image using a triangular data structure. A more general display algorithm is presented to transform the digital images into their respective graphic forms.

Abstract: difficulty differentiating color categories based on the orange color ramp, especially when using the six-color maps. These results supported further investigation and testing of other color ramps that provide a greater contrast between classes in a given ramp. Also, after seeing the difficulties respondents had with the dark boundary choropleth maps during the focus group and cognitive tests, we concluded both choropleth and isopleth maps should include light county boundaries. The two new maps below show the same general health data as the first two maps to the left, with a new divergent color ramp, which goes from red to blue. The new map format, designed to improve user accuracy in retrieving data from choropleth and isopleth maps, will be tested through an internet survey of approximately 400 public health researchers and professionals. Data from the internet survey will facilitate analysis of key issues such as users’ accuracy of data retrieval from choropleth versus isopleth maps, differences in data retrieval from national versus regional maps and users’ preferences for choropleth versus isopleth maps. These results will allow the CDC to determine the best format and features for providing online maps for BRFSS data users. Cognitive Assessment of Geospatial Survey Data

Abstract: The analysis of oceanographic data is a difficult task due to the large volume and multidimensionality of the data. Often is it necessary to aggregate other datasets to establish relationships and more complex analysis in order to answer environmental questions. Thus, this work aims to present different information visualization techniques (InfoVis) for oceanographic data concerning the most frequently used techniques, such as 2D and 3D Charts, Surface Map, Choropleth Map, and Line Map. For this purpose, a dataset of oceanographic buoys from the National Oceanic and Atmospheric Administration (NOAA) covering a period of 02 years (from 2015 to 2016) was used. This set of data was treated and classified according to the seasonal periods (winter, spring, summer, and autumn). The Rose Wind technique revealed that the wind speed average was between 10- 12 m/s. The Circle Parking technique showed a predominance of wind and waves from NE. In 2015, highest waves were recorded, mainly during the winter. The obtained results can be considered a useful tool for the assessment of the wind and waves relationship and help to coastal management strategies.