Publications by Ivan Lizarazo
How the sp method over works?
The GIS operation known as map overlay combines spatial features from one map layer with the attribute (numerical) properties of another. This R Markdown Notebook explains the R method over, which provides a consistent way to retrieve indices or attributes from a given spatial object (map layer) at the locations of another. It aims to help Percep...
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Landsat Image Exploration
Introduction This is an R Markdown Notebook which illustrates and extends instructions from the tutorial on remote sensing image analysis written by Aniruddha Ghosh and Robert J. Hijmans. In the original tutorial Ghosh and Hijmans describe how to access and explore satellite remote sensing data with R. They also show how to use them to make maps....
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Time series of MODIS vegetation indices
1. Introduction This notebook illustrates how to obtain time series of remote sensing data using a simple API. This notebook is written to help Geomatica Basica students at Universidad Nacional de Colombia to become familiar with geospatial functionalities provided by the R software environment. This notebook’s code follows closely the Web Time...
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Segmentation of natural color images
Introduction This notebook explores image segmentation for land cover classification. It aims to help Geomatica Basica students at Universidad Nacional de Colombia to become familiar with geospatial functionalities provided by R base and contributed libraries. Thus, our objective here is to develop a land classification of a given region based on...
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Access global soil data from R
1. Introduction This is an R Markdown Notebook which illustrates how to access SoilGrids using the webDAV protocol. In particular, it shows how to get soil layers for a region of interest. This notebook aims to help Geomatica Basica students at Universidad Nacional de Colombia to get started with Rgis. We will use gdalUTils functions to access an...
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Accessing elevation data from R
1. Why this notebook? This is an R Notebook created using R Studio on an old laptop. It illustrates several functionalities to obtain, process and visualize digital elevation models in R. It aims to help Geomatica Basica students at Universidad Nacional with their home activities during this time of social distancing. Everybody should publish a s...
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Leaflet - Part1
1. Introduction This is an R Markdown Notebook which illustrates how to read a text file with geographic coordinates, convert it into a spatial feature object, and create a leaflet map. This notebook is written to help Geomatica Basica students at Universidad Nacional de Colombia to get started with geospatial data in R. # install libraries from ...
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Getting started with Leaflet maps
1. Introduction This is an R Markdown Notebook which illustrates how to read a text file with geographic coordinates, convert it into a spatial feature object, and create a leaflet map. In addition, a shapefile of polygons is used to enhance the map contents. This notebook includes a workaround to publishing a map when uploading a html to RPubs c...
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Leaflet mapping using simplified geometries
1. Introduction This is an R Markdown Notebook which illustrates how to read a text file with geographic coordinates, and convert it into a spatial feature object with point geometries. Then, a shapefile of polygons is read. Finally, a leaflet map with polygons and points is created. This notebook is written to help Geomatica Basica students at U...
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Sentinel-2 in R
1. Introduction This is an R Markdown notebook which illustrates how to read, subset, and process a Sentinel-2 multispectral image in R. This notebook aims to help Geomatica Basica students at Universidad Nacional to get to know R geospatial functionalities. Previously, I downloaded a Sentinel 2 image over Bogota from the GloVis website. After un...
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