graduated classes are altered when saved to qgs

[qgib]

Author Name: Regis Haubourg (@haubourg)
Original Redmine Issue: 7217
Affected QGIS version: master
Redmine category:symbology

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confirmed on both 1.8 and master dc074b3.

when classifying continuous numerical data (shp - field type; real ; length 20; precision 5) , classes are generated correctly, but are saved with exponents notation if data exceeds 1000000:
In the following example, the last classe upper value has been converted from 6 034 292 to 6.03429e+06.
real max value is then thrown out of classes because 6.03429e+06 is converted to 6 034 290 when project is reloaded.
All the values close to upper and lower bounds are potentially concerned.

This is a blocker since there is no way to save a project correctly, except modifying classes by hand in a text editor.

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• fix_7217.patch (Alexander Bruy)
• Grauated_classes_test_sample.zip (Regis Haubourg)

[qgib]

Author Name: Regis Haubourg (@haubourg)

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QML and mapinfo tab are also concerned

[qgib]

Author Name: Regis Haubourg (@haubourg)

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It could be simple to solve since same problem occured with WMS bounds and scales:
here are some revisions solving thoses problems: [[https://issues.qgis.org/search/index/quantum-gis?q=exponential]]

[qgib]

Author Name: Regis Haubourg (@haubourg)

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conversion to Double seems to be done here:
[[https://github.com/qgis/Quantum-GIS/blob/master/src/core/symbology-ng/qgsgraduatedsymbolrendererv2.cpp]]
line 888:
double lowerValue = rangeElem.attribute( "lower" ).toDouble();
double upperValue = rangeElem.attribute( "upper" ).toDouble();

use of .toDouble seems to be done everywhere. Any idea ?

[qgib]

Author Name: Alexander Bruy (@alexbruy)

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Here is patch that should fix such issue. Unfortunately, I can't test it with wide range of datasets, so maybe in some cases it still don't work as expected.

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• pull_request_patch_supplied was changed from 0 to 1
• 5421 was configured as fix_7217.patch
• category_id was changed from Map Legend to 83

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• fix_7217.patch (Alexander Bruy) - Proposed patch

[qgib]

Author Name: Regis Haubourg (@haubourg)

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Hi, a little up to commiters: Can anyone test before merge ? This might be a easy-to-solve blocker ;-)
(I can't compile by myself and can only test ith osge4w).
Régis

[qgib]

Author Name: Nathan Woodrow (@NathanW2)

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Can we confirm if this still and issue. I can't reproduce here.

[qgib]

Author Name: Mathieu Pellerin - nIRV (Mathieu Pellerin - nIRV)

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I can't reproduce this issue either. So what they say is true, time does heal ;o)

[qgib]

Author Name: Nathan Woodrow (@NathanW2)

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Regis can you test with the latest build and report back if it is still an issue.

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• resolution was changed from to worksforme
• status_id was changed from Open to Closed

[qgib]

Author Name: Regis Haubourg (@haubourg)

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Hi, there is no new build on osgeo4w today, I'll try next week (QGIS training by the end of the week!)

[qgib]

Author Name: Regis Haubourg (@haubourg)

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Hi,
I must reopen, tested in e2bd04f today, problem is still here, qgs is still saved using scientific notation.
see:



<range symbol="2" lower="56" upper="1e+09" label="56.0000 - 1000000389.0000"/>

I join a very simple dataset to build unit tests:

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• 5817 was configured as Grauated_classes_test_sample.zip
• status_id was changed from Closed to Reopened

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• Grauated_classes_test_sample.zip (Regis Haubourg)

[qgib]

Author Name: Nathan Woodrow (@NathanW2)

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Ok I see it. Will try and fix.

[qgib]

Author Name: Minoru Akagi (@minorua)

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QVariant::toString() seems to return better results than QString::number(), doesn't it?

In python:

>>> from PyQt4.QtCore import *
>>> val = 6034292.
>>> QString.number(val)
PyQt4.QtCore.QString(u'6.03429e+06')
>>> QVariant(val).toString()
PyQt4.QtCore.QString(u'6034292')

>>> val = 1.000001
>>> QString.number(val)
PyQt4.QtCore.QString(u'1')
>>> QVariant(val).toString()
PyQt4.QtCore.QString(u'1.000001')

[qgib]

Author Name: Nathan Woodrow (@NathanW2)

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Seems so.

toString is the way to go.

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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Fixed in changeset "4538cf1593a22c1aba998abfc6f3c730b0943a71".

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• status_id was changed from Reopened to Closed