In QGIS 3.0, the vertex tool (same as node tool from QGIS 2.x) works a bit differently. Whether this is an improvement or not is a matter of opinion. It certainly takes a bit of getting used to.
Moving a vertex
2.x: Click on a vertex or segment to enable vertex editing for that feature. Click on vertex you want to move. Without releasing the mouse, drag it ...
Here's a python function that will select random features in a layer based on percent, ignoring current selection:
def SelectRandomByPercent (layer, percent):
#layer variable is the layer name in TOC
#percent is percent as whole number (0-100)
if percent > 100:
print "percent is greater than 100"
if percent < 0:
No need to create a new layer. You can show your layer's vertices using the Outline: Marker line Symbol layer type.
Just add a new symbol layer
Add a new symbol layer;
Choose Outline Marker line (top right corner);
In the Marker placement, Choose "On every vertex"
You can even style the marker to look like the red cross symbol used on layers in edit mode.
I don't think there's a really simple way to do this, but one way would be to:
Create a new polygon layer and create polygons over the areas you want to change the values of.
Code the polygons with the desired land cover value.
Convert the shapefile to a raster.
Use the Raster Calculator to substitute the new values.
Con(("POLYRAST" > 0),"...
The latest inserted vertices can be removed one by one by hitting either Del or BackSpace keys.
It really seems to be undocumented in the current QGIS 2.2 manual at http://docs.qgis.org/2.0/en/docs/user_manual/working_with_vector/editing_geometry_attributes.html. It would belong to the Adding Features section which tells at the moment only how to add ...
In QGIS you have a reshape tool: Reshape Feature in the Advance Digitising Toolbar. This is the icon of the tool
Like in ArcGIS, selecting the line that you want to reshape, use the tool to draw the new segment and right-click to confirm.
By default CSV layers cannot be edited. You have to save to a different format, e.g. Shapefile, before you can start editing.
There's a new plugin that solves this issue called Editable GeoCSV. It can handle x and y columns for points or a WKT column. For more details see http://giswiki.hsr.ch/Editable_GeoCSV_QGIS_Plugin
If I understood you correctly, you have to move the selection anchor first:
use edit tool and hold down the CTRL key
drag selection anchor to the corner of your borderline
More information in ArcGIS Help.
Since you're not worried about simultaneous edits on features, I'd say that in theory you have nothing to worry about. The main danger w/ QGIS is that simultaneous editors can stomp on each other's edits without noticing ("last edit wins").
For data under active editing with multiple users you might want to at least keep track of history, which you can do w/...
This should do it and is a little simpler than the examples in the online help for UpdateCursor which is nevertheless worth a read.
I've assumed your shapefile is in a folder called C:\temp and that structuretype is an integer field. If it is a text field just use "3" and "4" instead of 3 and 4.
features = arcpy.UpdateCursor(r"C:\temp\...
The best way is to convert this shape file to file-geodatabase and build the topology in ArcGIS for "Must Not Have Gaps" and "Must Not Overlap".
The important thing in building topology is cluster tolerance. This is a tolerance in which topology will remove/fix errors automatically after validating. So you should select this tolerance very carefully as big ...
In Snapping Options (Settings menu) enable snapping (better snapping to vertex only in your case as suggested in comments) for your layer, then using Split feature tool make a left click on the one blank space on side of the line, then make left click on the vertex where the split should occur and in the end make a right click on the blank space on the other ...
Generally, I also recommend using the spatial ecology tools as discussed by blah238.
However, another method you could try would be to add an attribute called Random to store a random number:
Then, using the field calculator on that attribute, with the Python Parser, use the following codeblock:
The problem was is no primary key.
In pgAdmin do this request.
ALTER TABLE tableName
ADD PRIMARY KEY (id);
Example for planet_osm_line table and setting osm_id column ,as primary key :
ALTER TABLE planet_osm_line
ADD PRIMARY KEY (osm_id);
untill osm_id is unique.
Using QGIS you can quickly divide a given shapefile up into regular rectangles as you've shown in your example.
Load the original shapefile;
Use Vector|Research Tools|Vector grid and create a grid of polygons the same extent as your shapefile, with the right distance between divisions ('parameters') selected (100 in my example image below);
Intersect the ...
If you want to interactivelly change your points coordinates, one by one, I believe you can do what you want by using the Numerical Vertex Edit Plugin. I can install it in Plugins > Fetch Python Plugins and search it by its name.
After installing you will notice a new icon on you digitalizing toolbar like this . To make it active you must be editing a layer....
There are two ways to get at the Create Features window from the Editor toolbar:
1) Start Editing. Right-click on toolbar and select "Editor"
2) In the editor toolbar: Editor > Editing Windows > Create Features
Alternatively, the right most button on the editor toolbar:
Start editing that shapefile, double click on said point, right click on point and "move to" and it will give you an option to type in the x and y coordinates for where you want to move the point to. the drop down also gives options to change to DD or meters etc.
QGIS comes with "offline editing" functionality in core. This downloads the data to a local spatialite database, so you can work on an offline copy and the delay caused by network roundtrips is gone. This is not a memory layer but if I understand correctly, that's just an example and not mandatory.
To enable offline editing, you have to check the offline ...
Possible workaround, maybe good as just temporary solution for few data:
Enable snapping (Settings --> Snapping Options...). Set snap to vertex and set some tolerance.
Create a "dummy" line feature snapped on vertices you want move.
In snapping option check Enable topological editing
Activate node tool and select vertices of "dummy" line and move (hold ...
The syntax problem is most likely caused be the spaces in column names. If you double-click the column names in field calculator, they will most certainly be added with quotation marks, e.g.
"Catt Pop" + "Buff Pop"
In the documentation, it is alluded to that you cannot edit data in a SQLite database from ArcMap:
You can connect from ArcGIS to an SQLite database to create maps and perform spatial analysis on your data.
However, the only place this appears to be explicitly stated by Esri is in the ArcGIS Discussion Forum:
Yes; you cannot edit data in a SQLite ...
It's not strictly read-only access. You can load data via copy/paste and import into a SQLite or SpatiaLite database. Tables and feature classes can be appended to using append or Load Data.
You can edit the SQLite/SpatiaLite data via code as Insert/Update/Delete are supported.
What you can't do is open an edit session in ArcMap.
The location coordinates of your feature are stored in a geometry/shape field in the attribute table, not a text readable field you can adjust. You can store the coordinates as attributes, but they won't actually control where the point is.
There are a few ways to address this:
First, you could just make a table/spreadsheet/csv of your coordinate