Fall 2010 11 520 11 188 Recitation 4 Class Review Nov 10 12 2010 KEY POINTS TOPICS Thematic Mapping LECTURE LAB Data classification method Quantile equal interval natural break Lab 1 Lab 2 Exclusion Exclusion visual representation what should be excluded Lab 4 Definition query calculation what should be included Remember to annotate the excluded features in your legend Projection system GIS Models Vector v s Raster attribute tables Select by attribute Querying attribute table or feature Local projected system lat lon system how to convert projection system from one to another how to assign a projection system to a layer Lab 2 Part III Lab 3 Part IV Lect Oct 6 Lect Sept 15 How to query a table to select the records of interest e g how to find out the minimum maximum mean value of a data column Sort ascending descending or check Statistics Lab 3 HW 1 Part 2 Select by location If you have features selected any of your subsequent operations are applied only to the selected features Field calculator When dividing a value using Field Calculator zero value records should be excluded first you can use definition query to preclude the zero value records or you can select by attribute to only select non zero valued records as denominators Lab 3 Part II Join table to a layer Join attributes from a table Lab 5 Lect Sept 22 Keep all records Keep only matching records HW 3 Part 1 Summarize in ArcGIS HW 1 Part 2 HW 2 Part 1 Database manipulation in Ms Access Lect Sept 22 Recitation 2 Census Geography Summary Levels Summary Files SF1 SF3 Lect Sept 29 Lab 5 Data Manipulation Aggregation Census Data Prepared by Lulu Xue and Shan Jiang Q A 11 520staff mit edu HW 1 Part 1 HW 2 Part 1 Page 1 of 2 Fall 2010 11 520 11 188 Recitation 4 Class Review Nov 10 12 2010 Spatial Analysis Vector Models Spatial Analysis Raster Models Buffer Dissolve to remove buffer feature overlap Lab 3 Part III Not all cases need to dissolve the resulting buffers In some cases Lab 6 individual buffer for each feature would be more reasonable Lect Oct 13 Union v s Intersect Recitation 3 Erase HW 1 Part 2 HW 2 Part 2 Spatial join Creates a table join where fields from one layer s attribute table are appended to another layer s attribute table based on the relative locations of the features in the two layers Raster analysis Convert features to raster Lect Oct 20 How to set up raster properties cell size mask area extent Lab 7 Recitation 3 Neighborhood statistics v s zonal statistics Spatial analyst tools HW 3 Part 1 Lect Nov 10 Not limited to the ones mentioned in the lab exercises or homework In cases where you need other functions you may refer to the ArcGIS online help for in depth guidance Spatial join also has summarizing function see examples in ArcGIS Desktop Help Index spatial joins aggregating fields If more than one join feature is found for a target feature and you want to maintain the exact same number of output features as Target features input features you need to set a Join merge rule The Join merge rule combines values from a single field for multiple rows in the join feature class when more than one join feature is found for a target feature For example a city land use feature class has a text field called LU containing two letter characters indicating each polygon s land use classification such as CO for commercial The land use feature class is then joined to a city district polygon feature class where the districts are the target of the spatial join The one to one join operation is chosen so the new feature class will have the same number of features as the original input districts but it will have the attributes of the land use feature class The Join merge rule was applied to the LU classification field with a comma as the delimiter Prepared by Lulu Xue and Shan Jiang Q A 11 520staff mit edu Page 2 of 2