2D Results Point Feature Export Question

[tmgreer]

Hello,

We are running into a post-processing error within the RAS mapper and are curious if anyone might have some guidance. We are trying to store/save to disk a velocity output map layer as a point feature. We would like to be able to use the point feature layer shapefile in ArcMap for our purposes.

We have tried to execute this and when the compute/update stored map command is selected, the following error is obtained: “Object reference not set to an instance of an object”. In the select point layer option under results map parameters, there appears to be a dropdown menu for selecting a “point layer” but it is inactive. This could be the problem but we cannot seem to figure out how to link to another file. We have exported the 2D flow area to a shapefile within the project folder but this does not seem to work.

Please help! Thanks in advance. Your time is much appreciated.

Kind Regards, -Tom G

[Toby]

You might consider using the HDF viewer and copying csv tables from there to create a shapefile in Arc. You will have to set the HDF parameters in your plan options to write the velocity data.

The data you want is under the following drop downs in the HDF file:

Results/Unsteady/Output/Output Blocks/Base Output/Unsteady Time Series/2D Flow Areas/”your mesh”/Node X Vel

Results/Unsteady/Output/Output Blocks/Base Output/Unsteady Time Series/2D Flow Areas/your mesh/Node Y Vel

Geometry/2D Flow Areas/”your mesh”/FacePoints Coordinate

https://support.hdfgroup.org/downloads/index.html

you want the viewer – HDFView 2.14

[tmgreer]

Hello Toby,

Thank you very much for the response. We have downloaded the HDFView 2.14 to take a look at the data. This program is pretty neat.

We are not seeing the Node X Vel and Node Y Vel options, but only the following:
Results/Unsteady/Output/Output Blocks/Base Output/Unsteady Time Series/2D Flow Areas/”your mesh”/Face Velocity

How do we get the Node X Vel and Node Y Vel options to appear? Can this be obtained from the Face Velocity output?

We have successfully obtained the FacePoints Coordinate data which appears to properly show the coordinates of the mesh points.

We would also be interested in any way of generating this data without a 3rd party software if at all possible to avoid any human error in processing the data. We are not familiar with the process to turn this data into a shapefile, but if we can get into a tabular format, it may suffice for our purposes. It would be very nice if the program could be used to store/save to disk a velocity output map layer as a point feature.

Kind Regards, -Tom G

[Toby]

Hi Tom,

To get the velocity data make sure you set it in the plan output options. Under the plan window -> Options -> Output Options… -> HDF5 Write Parameters -> check the Write Velocity data box.

In the HDF viewer you can Export the data to a text file. You can then use excel to get your data formatted into the right setup for an XY data import to Arc Map.

http://support.esri.com/en/technical-article/000012745

Good Luck,

[tmgreer]

Thanks Toby, we are now seeing the X & Y velocity data for the FacePoints.

We would also like to show some data for the Water Surface elevation, which appears to be provided for the Cells output rather than being correlated to the FacePoints. For example, in our model the water surface results have 91485 columns (which matches the rows in Geometry Cells Minimum Elevation) and the node velocities have 91084 columns (which matches the rows in FacePoints Coordinates).

Any idea of how to combine these into one master table? What might the extra 400 data fields be for?

Also, is there any output available for flow angle? We could also calculate per the velocity vectors if necessary.

Kind Regards, -Tom G

[Toby]

The WSE values match the cell centers data.

I use program R to make shapefiles from the HDF files, but that gets a bit tricky if you have never used R.

In the HDF viewer you can export a text file. Play around with it. Then merge the xy data and the velocity or WSE data in excel. This is a straight forward process you should be able to figure out. You will need to transpose the data to get the xy data to line up with the velocity or WSE data. Off the top of my head I can’t remember, but your runtime length should match your columns or rows and the data should match the other column or row count. Explore the HDF files….lots of good stuff in there!

runtime = “Results/Unsteady/Output/Output Blocks/Base Output/Unsteady Time Series/Time Date Stamp”

cellXY = “Geometry/2D Flow Areas/”,mesh,”/Cells Center Coordinate”

[kozskan]

Hi Toby,

I followed the discussion and I wonder if you have any clue how to create the static map of velocity arrows? I’ve extracted FacePoints Coordinate, Node X Vel and Node Y Vel in R from the HDF but I am kind of struggling with the structure of data used to create the layer that I want to use in qgis in order to create the map.

I assume it should be mesh layer but somehow can not create it along with the vectors that represents the actual flow direction. My aim is to create a static map, similiar to wind map, where the ground would be colored based on the flow rate (m3/s) and vectors would indicate the flow direction.

Thanks for any advice,
PK

[Chrym]

Hi @kozskan did you manage to figure this out?

[kozskan]

Hi Chrym,

Yes, I get the layer to the QGIS. The raster layer, where each sell was
representing the vector of velocity and its magnitude was converted to
points. Then I filtered small unwanted values which would mess the whole
layout (just set a threshhold). Then QGIS, in symbology of given point layer
you need to select the symbol (an arrow). The arrow symbol has its
properties – magnitude and orientation and both are yeilded by hecras (you
set it by opening the source fileld and choose the correct one in attribute
table). The raster layer underlaying the vector layer is just the same layer
which is stratified based on magnitude.

[Chrym]

Thank youy so much, such a lifesaver!

[Chrym]

Hi @kozskan, sorry to be a bother again. So you did not even use the HDF5 outputs at all to create your final map? You just used the ouputted static raster map direct from the results?
Please advise.
Thanks.

[Chrym]

Hi Tom. Did you finally figure out how to combine the seperate X, Y and Z matrices into one excel file?
I’m really stuck.

Thanks.

[Author]

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