area changes not calculating

[jrozek]

I have two urban area maps-1991 and 2006. The area changes calculates them as having the same land area and there is no change between them. I have the no data value set at 0 for each one. What is going wrong?

[KolesovDmitry]

Could you please provide your transition table? (Text version or a screenshot are both appropriate)

[jrozek]

Thanks so much for your response- I was able to get the Area Changes to be correct. I am entirely new to using Molusce and am working on a final project for my Advanced GIS class.

I have a new problem that I don't think is data-related. I can either run "update tables" or "create changes map" on the Area Changes tab but never both- the system either crashes or gives a "memory error" message if I try to do one after the other. Unfortunately, you need to do both to move on with the process. Any advice?

[bojanah345]

Hi! I've been experiencing similar problem: MOLUSCE calculates the class statistics and transition matrix correctly but as I hit the "Create changes map" button and specify the name of the resulting raster, QGIS crashes (Crash dumped). Every time. Any suggestions? Thank you! (I'm using QGIS 2.14.1-Essen version but the problem occured with previous versions as well.)

[mazingaro]

The solution is the reclassification of values!

After searching for the same answer answer as well I got responded by a user which wrote me: An additional tip: a friend had labeled categories in their map with numbers 101, 102, 103, 201, 202, 203, 301, 302, 303, and Molusce was crashing. We found that reclassifying the categories to small numbers: 1, 2, 3, ..., 8, 9, solved the issue. Hope you find a solution soon. Best regards

Reclassification with r.reclass worked for me after 2 days of headache and searching for complicated solutions :)

[palarifeen]

Dear, I have a problem during map validation for prediction purpose(validate the simulated map with actual map). I have added the screenshot. Please, suggest me to overcome the problem.

[reinhartcjp]

Greetings! When using MOLUSCE to generate Area Changes tables and map, I get an error message as stated. I have reclassified the features to one digit numbers and transform the raster from float to integer. Please help.

[cypressgithu]

The solution is the reclassification of values!

After searching for the same answer answer as well I got responded by a user which wrote me: An additional tip: a friend had labeled categories in their map with numbers 101, 102, 103, 201, 202, 203, 301, 302, 303, and Molusce was crashing. We found that reclassifying the categories to small numbers: 1, 2, 3, ..., 8, 9, solved the issue. Hope you find a solution soon. Best regards

Reclassification with r.reclass worked for me after 2 days of headache and searching for complicated solutions :)

Where is r.reclass exactly found

[cypressgithu]

How do l configure Grass in QGIS 2.18

[mazingaro]

I don't use QGIS 2 so I cannot help you with this + this question lack informations about your system, how did you install QGIS etc. In the mean time, QGIS got it's own reclassification alghoritm. You can also use GRASS GIS directly. So, I recommend you to do the reclassification in QGIS 3, GRASS or whenever else you want and then use this results in Molusce.

On Thu, 1 Dec 2022, 16:23 cypressgithu, @.***> wrote:

How do l configure Grass in QGIS 2.18

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[cypressgithu]

I have two urban landuse map which l classified using suppervised classification, with 3 classes each. 1 built-up, 2 unbuilt up and 3 water bodies.but lm having troubles creating a change map in MOLUSCE. ![Uploading Screenshot (21).png…]()

[cypressgithu]

Thank you for your support, much appreciated.

[K5ola]

Please I don't understand... Can use please elaborate it

[simgislab]

Try brand new MOLUSCE 4 for QGIS 3 and let us know if the problem persists