Join Videos

Videos make it easy to quickly apply the Join dialog.


Pending updates: The former Save update query check box in the Join dialog has been replaced with a new Setup Join and Edit Query button, which provides slightly different, but more convenient, operation.  The Join Component button has been renamed Join.   Videos may not have been updated with these changes.


Join Dialog Part 1 -  Spatial Joins - See the new Join dialog in action, effortlessly doing spatial joins without SQL.  Using a map with two layers, a cities layer showing cities in the US and a states layer showing states in the US we add the name of the state for each city to the cities attributes.   Next, we take data from the cities layer and add it to the states layer, summing up the populations for cities in each state to get a total population for the state, plus maximum and minimum city populations in that state.  Works in Viewer, too.


Join Dialog Part 2 - Joins between Tables - A fast-paced video showing three examples of joins between tables, with no SQL required:  We add a Publishers field to each title in a list of books (one to many) and then we show how with a single click we update the table to incorporate changes made and new data added.  Next, we add three new fields to the Publishers table to harvest data from books (many to one) to create fields that contains a list of titles, the average sales price of a book and the last publication date.   Finally, we show how to alter the saved query to update the list of titles into JSON format. Wow!  Works in Viewer, too.


Join Dialog Part 3 - Raster to Vector Joins - The third, action-packed video on the new Join dialog shows effortless raster to vector joins using a point and click dialog with no SQL required. Everybody thinks of joins as just between tables, but taking data from a raster to load into attributes in vector objects is just another join.  We use a single-channel raster that shows terrain elevation near Livermore, California, and use a point and click join to transfer the height of the terrain to points in a drawing layer above that terrain.  Next, we switch to a vector layer of parcels as areas, and transfer the average height of the terrain under each parcel, the maximum height and the minimum height, all done effortlessly with a point and click.  Along the way we show how to customize the update query to round values.  Easy!  Works in Viewer, too.


Join Dialog Part 4 - Joins into Queries - Everybody knows the Join dialog can take data from either tables or queries and join it into a target table, but amazingly, the Join dialog can also use a query as the target table as well. This fourth in the series of Join dialog videos shows how we can use the point and click dialog to do a join into a query, using the power of the query to organize how the joined data flows into tables the query uses.  We do a simple query first, and then we show how to do a join into only selected records.  Super!  Works with Viewer, too.


Join Dialog Part 5 - Vector to Raster Joins - We transfer attribute values from areas (polygons) in a drawing (vector layer) to pixels within those areas in a single-channel terrain elevation image (raster layer), showing how values can be calculated for pixels in regions where areas overlap. After doing the transfer in a default way, updating the single channel in the raster, we show a different workflow, using the Join dialog to automatically add a second channel to the raster and then transferring area values into that second channel.  Works for Viewer, too.


Join Dialog Part 6 - Raster to Raster Joins - Learn to do raster to raster (image to image) joins quickly and easily in the new Join dialog with a very useful example:  take three gray scale images with one channel each and combine them into a single RGB image using Join.  Next, we combine two RGB images by joining a blurred image into a full resolution image, to blur parts of the full resolution image that we want to hide.  That's a useful technique to respect privacy or for security purposes.  Works in Viewer, too.


Color Infrared for Free - See how easy it is to have many different visualizations of the same image, at the same time, without increasing storage space at all.  This fun video shows how to use NAIP four band imagery (red, green, blue, and infrared) to see the same data at the same time as a natural color RGB image, as a false color infrared image, and as higher contrast or other effects in both natural color and false color infrared.  Works in Viewer, too.


Knock Out Pixels Using Join and Alpha - Use the Join dialog to "knock out" (make transparent) those parts of an RGB image we do not want to see.  In just a few minutes using point and click dialogs and no SQL, we use a drawing that contains areas (polygons), showing areas of interest, to create a one-channel mask image that has zeros for pixel values within the areas, and 255 for pixel values outside the areas.  We then Join that mask image into our RGB image as a fourth channel.  We can then style the RGB image to use the fourth channel as an Alpha (transparency) channel.  That has the effect of leaving visible only those parts of the image within the areas.  We can use that image to great effect to show photographic coverage in some parts of a map, overlaid on terrain or street maps or other visualizations. Super!


Shuffle Channels with a Raster Self Join - See how easy it is to rearrange channels in an image using the Join dialog.  That's called a self-join and it is super easy to do!  We rearrange channels in a four channel image from the NAIP program that has Red, Green, Blue and Infrared channels into a Color Infrared presentation that can be exported in use for software that cannot map display channels on the fly.   Next, we show another example of saving a terrain elevation raster to a second channel within the same image, so we always have a backup that can be instantly restored if desired.  All that in under five minutes!  Wow!.  Works in the free Viewer, too.


Create RGB from RGBA using Join - We use the Join dialog to create a three channel, RGB image from a four channel image, all in under a minute with a few easy clicks in the Transform pane and Join dialog, no SQL required.   Manifold can present four channel images however we like, using the fourth channel or not for transparency, but many simpler packages may insist on using the fourth channel in a four channel image as an "alpha" transparency channel. That causes wrong effects when the fourth channel is infrared or some other data channel and not alpha.  The solution is easy, to quickly create a three channel image and to export that, so there are only three channels in the resulting TIF or other exported file, without any fourth channel to confuse other software.


Find Percentages of Open Space in ZIP Code Areas  -  Uses an SQL JOIN query, and not the Join dialog.  Given a layer of polygons representing ZIP codes and a layer of polygons showing open spaces like parks and green spaces, find the percentage of open space in each ZIP code area.   This video shows how to do that start to finish in a few simple steps, from initial importing of shape files to final results, in just five minutes, with an additional six minutes of explanation what each step does.  Works in Manifold Release 9 or using the free Manifold Viewer.


5 Minute Tutorial - Clip Part of an Image - A short Manifold video that shows how to create a new image that is part of a source image. We often work with large rasters where we need only part of the raster, so we would like to get a copy of only part of the bigger raster in a smaller image. This video shows how. Using a large, four channel image of the region near Cheyenne, Wyoming, we clip out part of the image to create a smaller, three channel image showing a storage area in Warren Air Force Base.


5 Minute Tutorial - Split Highways - In only five minutes we use the Split template cut operation to split interstate highways in the US by boundaries of US states, and then we transfer a state name to highway lines within that state by using the Join dialog. We round out the video by styling the result for a really super display.  

See Also



Join Examples