{"id":380,"date":"2018-05-03T14:35:49","date_gmt":"2018-05-03T12:35:49","guid":{"rendered":"https:\/\/blogs.fu-berlin.de\/reseda\/?page_id=380"},"modified":"2019-07-23T13:35:53","modified_gmt":"2019-07-23T11:35:53","slug":"regression-in-r","status":"publish","type":"page","link":"https:\/\/blogs.fu-berlin.de\/reseda\/regression-in-r\/","title":{"rendered":"Regression in R"},"content":{"rendered":"<p>Very high-resolution reference data are usually difficult to obtain or only available for small areas of the study area. However, low-resolution data, such as Landsat 8 (30 m), are available in a high spatio-temporal resolution. Using a regression method, we can create sub-pixel information by relating the high-resolution information to very low-resolution Landsat 8 pixels.<\/p>\n<p>We want to perform a Support Vector Regression in order to regress proportions of imperviousness for each Landsat 8 pixel in Berlin. For this we will use two data sets in this section:<\/p>\n<ol>\n<li>a <a href=\"https:\/\/box.fu-berlin.de\/s\/ztHcGQtXMKJbcXN\/download?path=%2FShapfiles&amp;files=reg_train_data.zip\"><strong>shapefile containing very high-resolution land cover information<\/strong><\/a> (including imperviousness), based on a digitized digital orthophoto of 2016 (<a href=\"https:\/\/www.stadtentwicklung.berlin.de\/umwelt\/umweltatlas\/edua_index.shtml\" target=\"_blank\" rel=\"noopener\">Berlin Environmental Atlas<\/a>)<\/li>\n<li>a <a href=\"https:\/\/box.fu-berlin.de\/s\/ztHcGQtXMKJbcXN\/download?path=%2FLandsat_Data&amp;files=LC081930232017060201T1-SC20180613160412.tif\"><strong>Landsat 8 acquisition<\/strong> <\/a>(ID: LC08_L1TP_193023_20170602_20170615_01_T1), which you may already have acquired during the <a href=\"https:\/\/blogs.fu-berlin.de\/reseda\/earthexplorer-exercise\/\" target=\"_blank\" rel=\"noopener\">L8 Download Exercise<\/a><\/li>\n<\/ol>\n<p><a href=\"https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-2637\" src=\"https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002.png\" alt=\"\" width=\"1919\" height=\"949\" srcset=\"https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002.png 1919w, https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002-300x148.png 300w, https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002-768x380.png 768w, https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002-1024x506.png 1024w, https:\/\/blogs.fu-berlin.de\/reseda\/files\/2018\/09\/reg_002-1200x593.png 1200w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><\/a><\/p>\n<div style=\"margin: -30px 0 20px 0;text-align: center\"><span style=\"color: #686868;font-size: small\">Landsat 8 scene overlaid by the shapefile (colored by classes) in QGIS. The different detail levels become very clear in this visualization<\/span><\/div>\n<div style=\"background-color: #f1f1f1;padding: 18px 30px 1px\">\n<h1>Section in a Box<\/h1>\n<p><a href=\"https:\/\/blogs.fu-berlin.de\/reseda\/prepare-samples-for-regression\/\"><strong>Prepare the samples for training<\/strong><\/a><br \/>\n&#8211; learn how to preprocess your shapefile<br \/>\n&#8211; extract raster features and percentages of your target class (e.g., imperviousness)<br \/>\n&#8211; create your training data set for regression analysis<br \/>\n<a href=\"https:\/\/blogs.fu-berlin.de\/reseda\/svm-regression\/\"><strong>SVM Regression<\/strong><\/a><br \/>\n&#8211; learn how to perform a Support Vector Regression (SVR) in R using the e1071 package<br \/>\n&#8211; predict the whole image data based on your regression model<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<hr style=\"height: 4px;background-color: #6b9e1f\" \/>\n<div style=\"font-family: 'Noto Sans', sans-serif;line-height: 1.2;text-align: right\"><span style=\"font-size: 12px;color: #bfbfbf\"><strong><em>NEXT<\/em><\/strong><\/span><br \/>\n<a style=\"text-decoration: none\" href=\"https:\/\/blogs.fu-berlin.de\/reseda\/prepare-samples-for-regression\/\"><span style=\"font-size: 30px;color: #6b9e1f\"><strong><em>PREPARE SAMPLES FOR REGRESSION<\/em><\/strong><\/span><\/a><\/div>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Very high-resolution reference data are usually difficult to obtain or only available for small areas of the study area. However, low-resolution data, such as Landsat 8 (30 m), are available in a high spatio-temporal resolution. Using a regression method, we can create sub-pixel information by relating the high-resolution information to very low-resolution Landsat 8 pixels. &hellip; <a href=\"https:\/\/blogs.fu-berlin.de\/reseda\/regression-in-r\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Regression in R&#8221;<\/span><\/a><\/p>\n","protected":false},"author":3237,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-380","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/pages\/380","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/users\/3237"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/comments?post=380"}],"version-history":[{"count":13,"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/pages\/380\/revisions"}],"predecessor-version":[{"id":2954,"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/pages\/380\/revisions\/2954"}],"wp:attachment":[{"href":"https:\/\/blogs.fu-berlin.de\/reseda\/wp-json\/wp\/v2\/media?parent=380"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}