In QGIS 3.4.4, using the Field Calculator, the expression  round(-2.040,1)   returns   -1.9   where I expected it to return  -2   Converting the field to real round(to_real(-2.040),1) did not change anything.  In QGIS 2.18.19 and got the expected result.  Is the syntax changed in 3.x or is this a (known) bug? Or am I expecting the wrong output?
122088
I created a grid of rectangular polygons with the Create Grid function, from the Vector Creation group of the Processing Toolbox in QGIS 3.4.2. The rectangles measure half a degree of longitude by half a degree of latitude.    When I want to label the polygons, I write an expression that rounds the values of latitude and longitude attributes to 2 decimal places, since the attributes created in the grid brings many decimal places.    But the round function rounds the values badly.    I know that I can create new attributes that express the coordinates with fewer decimal places and label the entities based on those attributes, but I was struck by the behavior of the function. I expected it to round to the nearest value.    Does anyone know what the problem is that the round function wrongly rounds off the decimal number?    Attached screenshots of Source Fields and the Attribute Table.
96922
Why when I save a value of say 40.54 in SQL Server to a column of type Real does it return to me a value that is more like 40.53999878999 instead of 40.54?  I've seen this a few times but have never figured out quite why it happens.  Has anyone else experienced this issue and if so causes it?
8736
I'm trying to calculate the NDVI using raster calculator, but the result is integer instead of decimal.  NDVI = (NIR - RED)/(NIR + RED)   The result is normally in the range -1 to 1, but when i tried to calculate de result is -1, 0 and 1, and it does not have have any number in between like, -0.9 or 0.1. And i need those values so i can classify the result in term of soil occupation
72082
I have tried this on my Windows 7 calculator with $\sqrt9 -3 $ it too gives some weird answer- ie$1.1546388020691628168216106791278e-37$. And so for any $n$(positive) $\sqrt n^2-n= wierd_ .answer$ Why does this happen?
56805
I work on QGIS 2.2, and I am unable to edit my attribute table to change the field type from string to double.  I have gone through several tutorials. - I can not run the table manager plugin, probably because its latest version is for qgis 2.0, (well it appears broken on my plugin manager UI).   I am unable to edit my layer so that I can use the field calculator (as several tutorials stipulated). I am not versed with python to use the python console
92789
I have a problem with the new QGIS version (2.16.0 or 2.16.1 Nodebo). I want to sort numeric values in the attribute table by clicking on the field name. But in contrast to older QGIs versions the attributes are not sorted correctly. It feels like QGIS recognizes it as text. but in the layer properties under fields it says the attributes are numeric (double or integer).
89167
I've seen the result repeatedly that $\text{Ext}(-,k) =0$ when $k$ is a field. I am yet to see a justification of this however.
80556
What's going on?! Subtraction works fine until I get to 0.1 - 0.1. I'm in visual c# 2008 using the nonoba.com API.  Console.WriteLine("hit! " + Users[targetNum].character.health + " : " + player.character.profile.attackPower);  Users[targetNum].character.health -= player.character.profile.attackPower;  Console.WriteLine("health! " + Users[targetNum].character.health);   output:  hit! 0.1 : 0.1 health! 1.490116E-08   Thanks all - I might use the decimal type, as I'm normally adding/subtracting nice "round" numbers. For now I'll just go with:  if (Users[targetNum].character.health &lt;= 0.00001)   By the way I knew this wasn't really going to be a "bug" in c# - I thought it would either by a bug in my code or some lack of understanding, which it was.  Having read all the recommended reading, I'm going to conclude that my folly was due to normally using the ActionScript Number type, which maybe has a decimal rather than binary floating point - anyway, it would never give this output.
21536
I have a raster with float number values for example: 2.544459104537964 and I want to round these up to integers. I have seen other posts on ArcGIS like  but when I use Raster Calculator in QGIS, Int(myraster + 0.5) only makes the first value (which is 0) to 0,5 and the last one (which is 100) to 100,5. The other pixels stay float.
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Is there a function to round a float in C or do I need to write my own?       float conver = 45.592346543;   I would like to round the actual value to one decimal place, conver = 45.6.
8350
I have the code  \documentclass{amsart}  \begin{document}     \begin{equation}         ]-\pi,0[ \qquad -\pi \qquad \int_{-\pi}^0 \qquad [-\pi,0]     \end{equation} \end{document}   which produces    Why is the minus sign on the left so far away from pi and how can this be avoided?
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I've been trying to use decimal values as params for a field attribute but I get a compiler error.  I found this blog post  saying it wasn't possible in .NET to use then, does anybody know why they choose this or how can I use decimal params?
98573
I'm trying to show that $Q[\sqrt3]$ is a field. I am particularly struggling with showing that every element is a unit.   So for some element, we want to show that for some element $a+b\sqrt3$, there exists $c+d\sqrt3$ in $Q[\sqrt3]$ such that $(a+b\sqrt3)(c+d\sqrt3) = 1$.  Is that the right direction? I am not really sure of how to come up with that inverse though. Any help would be appreciated.
40402
Is there any way to save frequently used expressions in the selection or field calculator dialogs? Obviously I can cut and paste them into a file where I might save them, but I mean within the context of QGIS like you can do in ArcMap.
13122
Is there a way to concatenate fields in field calculator of QGIS? (e.g. hectares + ' ha')
82915
For example, the standard division symbol '/' rounds to zero:  &gt;&gt;&gt; 4 / 100 0   However, I want it to return 0.04. What do I use?
77569
I am trying to write an ELSEIF conditional statement in QGIS Field Calculator (version 1.8.0). I have used an example I found online:  CASE WHEN val &lt; 0 THEN 'negative'   WHEN val = 0 THEN "neutral'   ELSE 'positive' END   I modified the statement as follows:  CASE WHEN  "GRID_ID"  = 1 THEN 'complete'   ELSEIF  "GRID_ID"  = 2 THEN "in progress'   ELSE 'not started' END   This statement would not run, the Output preview stated Expression is invalid.  The more info stated: Parser Error: syntax error, unexpected COLUMN_REF, expecting WHEN or ELSE or END  If anyone has had this error, what did you do to fix it?