If you are facing the first barrier, keep this article in a safe place\nsince it will serve you one day, but nor right now. On the other side if you\nare facing the second barrier, we will try to overcome it together.
\nThere are two main types of iterators; those looking for multiple layers of\ndata and those looking for multiple entities in a single data layer. <\/p>\n\n\n\n
In this article we will only discuss the first type of iterators, those\nthat will look for several layers of input data. In a separate article we will discuss\nthe other iterators. \n\nWe’ll follow the examples with ArcGis Pro \n\n\n\n<\/p>\n\n\n\n \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nbut\nit’s the same for ArcMap. \n\n\n\n<\/p>\n\n\n\n \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nLet’s\nconsider a simple model: \n\n\n\n<\/p>\n\n\n\n It can get really complicated but, at last, you will get a (sometimes various)\nblue ellipse representing the input data, and one (or more) green ellipse\nrepresenting the output data. <\/p>\n\n\n\n When we want to use the iterators, we have to focus on these two\nellipses and forget about the rest of the model. <\/p>\n\n\n\n First step:<\/strong> For the model to work on different batches of\ninput data, it will be necessary to choose the type of iterator. <\/p>\n\n\n\n Second step:<\/strong> we will set it up and format it to do exactly what\nwe want. <\/p>\n\n\n\n Third step:<\/strong> we must analyze what type of output we want, and\nhere there are two possibilities: <\/p>\n\n\n\n When the previous has been done, the problem is virtually solved. Before\nseeing the different iterators, it is important to know how to link the first\nand the last step. \n\nMost iterators have a structure of this type: \n\n\n\n<\/p>\n\n\n\n The iterator produces two outputs: <\/p>\n\n\n\n It is this variable that we will use to customize the model output layer,\nusually by adding this name in the output layer. As each input layer has a\ndifferent name, the corresponding output layer will also have a different name.\n<\/p>\n\n\n\n Last but not least: most iterators are limited in scope. They will look\nfor a data layer type in a restricted space that can be either a workspace or a\ngeodatabase (feature dataset). Before complicating the task with layers\ndistributed everywhere on your disks, please consider, if possible, to gather\nthem in a single directory or geodatabase. <\/p>\n\n\n\n How to decide which is the right iterator?<\/strong> <\/p>\n\n\n\n To answer this question, it is, usually, just enough to set the problem\nin plain English: for example \u00ab\u00a0I want to apply my model to all the\nimages of a directory\u00a0\u00bb<\/em> or \u00ab\u00a0I want to apply the model to all\npolygon layers of my geodatabase \u00ab\u00a0<\/em> , etc … <\/p>\n\n\n\n Let’s look at the most frequent cases and the corresponding iterators: <\/p>\n\n\n\n Iterate Datasets<\/strong><\/p>\n\n\n\n You define the directory or geodatabase containing the datasets The DATASET output must be connected to the first tool of the model. You define the directory or geodatabase containing the feature classes The Feature Class output must be connected to the first tool in the\nmodel. You define the directory containing the files The FILE output must be connected to the first tool of the model. You define the directory or geodatabase containing the feature classes The RASTER output must be connected to the first tool of the model. You define the directory or geodatabase containing the tables The TABLE output must be connected to the first tool of the model. You define the directory containing the geodatabases or directories. The output WORKSPACE must be connected to the first tool of the model. Name of the resulting layer<\/strong> <\/p>\n\n\n\n By opening the last tool of a model, you will always find the \u00ab\u00a0Output\u00a0\u00bb\nfield, where you will define the place and the name of the resulting layer. For\nexample: <\/p>\n\n\n\n C: \\ Users \\ admin \\ Documents \\ ArcGIS \\ Projects\n\\ MyProject10 \\ HYDROGRAPHIE_SURFACIQUE.shp<\/em> <\/p>\n\n\n\n So that, at each iteration, the resulting layer has a different name (if\nnot each consecutive output overwrites the previous one) you have to add a\nvariable element in the name. <\/p>\n\n\n\n This element will be the iterator output NAME. To insert NAME into the layer\noutput name, simply insert NAME between % in the desired place of the string\nname, for example: <\/p>\n\n\n\n C: \\ Users \\ admin \\ Documents \\ ArcGIS \\ Projects\n\\ MyProject10 \\ HYDROGRAPHIE_SURFACIQUE_% NAME% .shp<\/em> <\/p>\n\n\n\n At each iteration, % NAME% will be substituted by the name of the input\nlayer. <\/p>\n\n\n\n If you have held so far, you deserve to read the next article where we\nwill discuss other types of iterators that play a role in a layer features. <\/p>\n","protected":false},"excerpt":{"rendered":" There are always two psychological barriers to overcome with Model Builder: the first one is deciding to, actually, use it and move from the interactive, natural working mode to ArcMap, i.e. to a working mode where…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"give_campaign_id":0,"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"sfsi_plus_gutenberg_text_before_share":"","sfsi_plus_gutenberg_show_text_before_share":"","sfsi_plus_gutenberg_icon_type":"","sfsi_plus_gutenberg_icon_alignemt":"","sfsi_plus_gutenburg_max_per_row":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1260],"tags":[],"class_list":["post-8267","post","type-post","status-publish","format-standard","hentry","category-non-classe-en"],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p6XU0A-29l","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts\/8267","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/comments?post=8267"}],"version-history":[{"count":0,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts\/8267\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/media?parent=8267"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/categories?post=8267"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/tags?post=8267"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/111.png?resize=219%2C385&ssl=1\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/112.png?resize=483%2C388&ssl=1\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/113.png?resize=609%2C295&ssl=1\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/114.png?resize=630%2C242&ssl=1\")
<\/figure>\n\n\n\n\n Expression\n of the iterator<\/strong> \n <\/td> \n Iterator\n to use<\/strong> \n <\/td><\/tr> \n datasets\n of a given type (raster, feature class, tile, …) in a directory or\n geodatabase \n <\/td> \n Iterate\n Datasets (Datasets) \n <\/td><\/tr> \n the\n feature classes of a given type (polygons, lines, points …) shapes of a\n directory or feature classes of a geodatabase \n <\/td> \n Iterate\n feature classes \n <\/td><\/tr> \n the\n files of a directory \n <\/td> \n Iterate\n Files (files) \n <\/td><\/tr> \n rasters\n of a certain format from a directory or a geodatabase \n <\/td> \n Iterate\n rasters (rasters) \n <\/td><\/tr> \n tables\n in a directory or geodatabase \n <\/td> \n Iterate\n tables \n <\/td><\/tr> \n the\n sub-workspaces of a workspace (the geodatabases of a directory, …) \n <\/td> \n Iterate\n Workspaces (workspaces) \n <\/td><\/tr><\/tbody><\/table>\n\n\n\n ![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/115.png?resize=387%2C441&ssl=1\")
<\/figure>\n\n\n\n
\nYou can use a mask name of (with *)
\nYou define the type of dataset to be processed by selecting it from the list
\nYou check the Recurrent box if you want to take into account also the\nsubdirectories in the directory <\/p>\n\n\n\n
\nThe output Name will be used for the output data (see below) Iterate feature classes<\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/116.png?resize=390%2C366&ssl=1\")
<\/figure>\n\n\n\n
\nYou can use a mask name of (with *)
\nYou define the type of feature classes to process by selecting it from the list\n
\nYou check the Recurrent box if you want to take into account also the\nsubdirectories in the directory <\/p>\n\n\n\n
\nThe output Name will be used for the output data (see below) Iterate Files<\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/117.png?resize=390%2C276&ssl=1\")
<\/figure>\n\n\n\n
\nYou can use a mask name of (with *)
\nYou define the extension to take into account (TXT, ASC, …)
\nYou check the Recurrent box if you want to take into account also the\nsubdirectories in the directory <\/p>\n\n\n\n
\nThe output Name will be used for the output data (see below) Iterate Rasters<\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/118.png?resize=390%2C516&ssl=1\")
<\/figure>\n\n\n\n
\nYou can use a mask name of (with *)
\nYou define the type of raster to be processed by selecting it from the list
\nYou check the Recurrent box if you want to take into account also the\nsubdirectories in the directory <\/p>\n\n\n\n
\nThe output Name will be used for the output data (see below) Iterate tables<\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/119.png?resize=381%2C267&ssl=1\")
<\/figure>\n\n\n\n
\nYou can use a mask name of (with *)
\nYou define the type of table to be processed by selecting it from the list
\nYou check the Recurrent box if you want to take into account also the\nsubdirectories in the directory <\/p>\n\n\n\n
\nThe output Name will be used for the output data (see below) Iterate Workspaces<\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2019\/03\/1110.png?resize=390%2C288&ssl=1\")
<\/figure>\n\n\n\n
\nYou can use a mask name of (with *)
\nYou define the type of workspace to process by selecting it from the list
\nYou check the Recurrent box if you want to take into account also the\nsubdirectories in the directory <\/p>\n\n\n\n
\nThe output Name will be used for the output data (see below) <\/p>\n\n\n\n