Fuel calcualtion and formula size

Hello,
I have some problems with fuel calculation and formula size
I have truck with 940 liters fuel tank and two fuel sensors with a calibration table for every sensor.
Like this:

2027 - 0 L
2061 - 20 L
2093 - 40 L
2122 - 60 L
2151 - 80 L
2179 - 100 L

I wrote a formula to calculate intermediate values and it works fine!
Formula like this:

io201 < 2027 ? 0:
(io201 >= 2027 && io201 <2061)? io201 = ( 0.588235294 * io201) + -1192.352941:
(io201 >= 2061 && io201 <2093)? io201 = ( 0.625 * io201) + -1268.125:
(io201 >= 2093 && io201 <2122)? io201 = ( 0.689655172 * io201) + -1403.448276:
(io201 >= 2122 && io201 <2151)? io201 = ( 0.689655172 * io201) + -1403.448276:
(io201 >= 2151 && io201 <2179)? io201 = ( 0.714285714 * io201) + -1456.428571:
(io201 >= 2179 && io201 <2208)? io201 = ( 0.689655172 * io201) + -1402.758621:
(io201 >= 2208 && io201 <2235)? io201 = ( 0.740740741 * io201) + -1515.555556:

total fuel value is calculated like (sensor1 + sensor2) / 2 and it works too! But only with TEST button. When i try to save formula - i have an error

Column 'attribute' cannot be null - SQLIntegrityConstraintViolationException (... < QueryBuilder:469 < DatabaseStorage:95 < BaseObjectResource:71 < ...)

Total formula size is 7068 lenth and 97 lines and it works only with TEST button.

Then i tried to separate formula for every sensor and then calculate it with third formula.
io201 - hardware sensor 1
io203 - hardware sensor 2

I created computed attributes that calculate io201 to io2201 in liters (and io203 to io 2203 too).
I connected the virtual sensors with the device.
Then i have two virtual computed attributes (io2201 and io2203) in liters that displayed in device sensors list.

Finally I tried to calculate FUEL with third formula math:round((io2201 + io2203)/2) and it works with TEST Button! But does not save fuel in the list of device sensors.
P.S. Of course, I connected the third formula to the device

What am I doing wrong?
Why does the TEST button works but does not save the Fuel data?

Anton Tananaev2 years ago

The problem is not with the formula. The problem is that you have not selected the attribute.

Victor Kyryllov2 years ago

In third formula i selected Attribute Fuel from drop down menu, like in another devices.
And connected to device this computed attribute.
If i chadged this formula from

math:round((io2201 + io2203)/2)
to
math:round((io201 + io203)/2) Fuel parametr appears!

I only change virtual sensors to hardware.
In both cases, the TEST button works. But the fuel parameter appears only if there is a hardware sensor in the formula.
With virtual sensors fuel parameter does not appear.

Anton Tananaev2 years ago

Have you waited for new data? Have you checked logs for errors?

Victor Kyryllov2 years ago

In the logs I found an error regarding this attribute and device

2023-03-03 17:27:51  WARN: Attribute computation error - org.traccar.handler.ComputedAttributesHandler.computeAttribute:105@1:13 variable 'io2201' is undefined - Variable (ComputedAttributesHandler:105 < *:115 < BaseDataHandler:27 < ... < *:29 < ... < *:29 < ... < *:29 < ... < GeocoderHandler:81 < ...)

But TEST button show correct value. Maybe try copy attributes?

Anton Tananaev2 years ago

Have you read our computed attributes documentation? Specifically I'm referring to this part:

The order in which computed attributes are applied to the device is not defined. It is therefore not recommended to use the result of one computed attribute in another computed attribute.

Victor Kyryllov2 years ago

But how can i use huge formula more then 4096 symbols?

This formula works fine with TEST button. But a cant save it.

math:round(((
io201 < 2027 ? 0:
(io201 >= 2027 && io201 <2061)? io201 = ( 0.588235294 * io201) + -1192.352941:
(io201 >= 2061 && io201 <2093)? io201 = ( 0.625 * io201) + -1268.125:
(io201 >= 2093 && io201 <2122)? io201 = ( 0.689655172 * io201) + -1403.448276:
(io201 >= 2122 && io201 <2151)? io201 = ( 0.689655172 * io201) + -1403.448276:
(io201 >= 2151 && io201 <2179)? io201 = ( 0.714285714 * io201) + -1456.428571:
(io201 >= 2179 && io201 <2208)? io201 = ( 0.689655172 * io201) + -1402.758621:
(io201 >= 2208 && io201 <2235)? io201 = ( 0.740740741 * io201) + -1515.555556:
(io201 >= 2235 && io201 <2262)? io201 = ( 0.740740741 * io201) + -1515.555556:
(io201 >= 2262 && io201 <2281)? io201 = ( 1.052631579 * io201) + -2221.052632:
(io201 >= 2281 && io201 <2316)? io201 = ( 0.571428571 * io201) + -1123.428571:
(io201 >= 2316 && io201 <2342)? io201 = ( 0.769230769 * io201) + -1581.538462:
(io201 >= 2342 && io201 <2367)? io201 = ( 0.8 * io201) + -1653.6:
(io201 >= 2367 && io201 <2393)? io201 = ( 0.769230769 * io201) + -1580.769231:
(io201 >= 2393 && io201 <2418)? io201 = ( 0.8 * io201) + -1654.4:
(io201 >= 2418 && io201 <2442)? io201 = ( 0.833333333 * io201) + -1735:
(io201 >= 2442 && io201 <2466)? io201 = ( 0.833333333 * io201) + -1735:
(io201 >= 2466 && io201 <2489)? io201 = ( 0.869565217 * io201) + -1824.347826:
(io201 >= 2489 && io201 <2514)? io201 = ( 0.8 * io201) + -1651.2:
(io201 >= 2514 && io201 <2539)? io201 = ( 0.8 * io201) + -1651.2:
(io201 >= 2539 && io201 <2564)? io201 = ( 0.8 * io201) + -1651.2:
(io201 >= 2564 && io201 <2589)? io201 = ( 0.8 * io201) + -1651.2:
(io201 >= 2589 && io201 <2613)? io201 = ( 0.833333333 * io201) + -1737.5:
(io201 >= 2613 && io201 <2640)? io201 = ( 0.740740741 * io201) + -1495.555556:
(io201 >= 2640 && io201 <2665)? io201 = ( 0.8 * io201) + -1652:
(io201 >= 2665 && io201 <2689)? io201 = ( 0.833333333 * io201) + -1740.833333:
(io201 >= 2689 && io201 <2714)? io201 = ( 0.8 * io201) + -1651.2:
(io201 >= 2714 && io201 <2738)? io201 = ( 0.833333333 * io201) + -1741.666667:
(io201 >= 2738 && io201 <2763)? io201 = ( 0.8 * io201) + -1650.4:
(io201 >= 2763 && io201 <2787)? io201 = ( 0.833333333 * io201) + -1742.5:
(io201 >= 2787 && io201 <2813)? io201 = ( 0.769230769 * io201) + -1563.846154:
(io201 >= 2813 && io201 <2837)? io201 = ( 0.833333333 * io201) + -1744.166667:
(io201 >= 2837 && io201 <2861)? io201 = ( 0.833333333 * io201) + -1744.166667:
(io201 >= 2861 && io201 <2885)? io201 = ( 0.833333333 * io201) + -1744.166667:
(io201 >= 2885 && io201 <2909)? io201 = ( 0.833333333 * io201) + -1744.166667:
(io201 >= 2909 && io201 <2935)? io201 = ( 0.769230769 * io201) + -1557.692308:
(io201 >= 2935 && io201 <2959)? io201 = ( 0.833333333 * io201) + -1745.833333:
(io201 >= 2959 && io201 <2982)? io201 = ( 0.869565217 * io201) + -1853.043478:
(io201 >= 2982 && io201 <3007)? io201 = ( 0.8 * io201) + -1645.6:
(io201 >= 3007 && io201 <3031)? io201 = ( 0.833333333 * io201) + -1745.833333:
(io201 >= 3031 && io201 <3055)? io201 = ( 0.833333333 * io201) + -1745.833333:
(io201 >= 3055 && io201 <3080)? io201 = ( 0.8 * io201) + -1644:
(io201 >= 3080 && io201 <3106)? io201 = ( 0.769230769 * io201) + -1549.230769:
(io201 >= 3106 && io201 <3132)? io201 = ( 0.769230769 * io201) + -1549.230769:
(io201 >= 3132 && io201 <3158)? io201 = ( 0.769230769 * io201) + -1549.230769:
(io201 >= 3158 && io201 <3186)? io201 = ( 0.714285714 * io201) + -1375.714286:
(io201 >= 3186 && io201 <3216)? io201 = ( 0.666666667 * io201) + -1224:
io201 > 3216 ? 940:0)
+(io203 < 2030 ? 0:
(io203 >= 2030 && io203 <2063)? io203 = ( 0.606060606 * io203) + -1230.30303:
(io203 >= 2063 && io203 <2094)? io203 = ( 0.64516129 * io203) + -1310.967742:
(io203 >= 2094 && io203 <2124)? io203 = ( 0.666666667 * io203) + -1356:
(io203 >= 2124 && io203 <2153)? io203 = ( 0.689655172 * io203) + -1404.827586:
(io203 >= 2153 && io203 <2181)? io203 = ( 0.714285714 * io203) + -1457.857143:
(io203 >= 2181 && io203 <2209)? io203 = ( 0.714285714 * io203) + -1457.857143:
(io203 >= 2209 && io203 <2236)? io203 = ( 0.740740741 * io203) + -1516.296296:
(io203 >= 2236 && io203 <2264)? io203 = ( 0.714285714 * io203) + -1457.142857:
(io203 >= 2264 && io203 <2291)? io203 = ( 0.740740741 * io203) + -1517.037037:
(io203 >= 2291 && io203 <2318)? io203 = ( 0.740740741 * io203) + -1517.037037:
(io203 >= 2318 && io203 <2345)? io203 = ( 0.740740741 * io203) + -1517.037037:
(io203 >= 2345 && io203 <2371)? io203 = ( 0.769230769 * io203) + -1583.846154:
(io203 >= 2371 && io203 <2396)? io203 = ( 0.8 * io203) + -1656.8:
(io203 >= 2396 && io203 <2421)? io203 = ( 0.8 * io203) + -1656.8:
(io203 >= 2421 && io203 <2446)? io203 = ( 0.8 * io203) + -1656.8:
(io203 >= 2446 && io203 <2471)? io203 = ( 0.8 * io203) + -1656.8:
(io203 >= 2471 && io203 <2494)? io203 = ( 0.869565217 * io203) + -1828.695652:
(io203 >= 2494 && io203 <2516)? io203 = ( 0.909090909 * io203) + -1927.272727:
(io203 >= 2516 && io203 <2542)? io203 = ( 0.769230769 * io203) + -1575.384615:
(io203 >= 2542 && io203 <2567)? io203 = ( 0.8 * io203) + -1653.6:
(io203 >= 2567 && io203 <2592)? io203 = ( 0.8 * io203) + -1653.6:
(io203 >= 2592 && io203 <2616)? io203 = ( 0.833333333 * io203) + -1740:
(io203 >= 2616 && io203 <2638)? io203 = ( 0.909090909 * io203) + -1938.181818:
(io203 >= 2638 && io203 <2662)? io203 = ( 0.833333333 * io203) + -1738.333333:
(io203 >= 2662 && io203 <2687)? io203 = ( 0.8 * io203) + -1649.6:
(io203 >= 2687 && io203 <2711)? io203 = ( 0.833333333 * io203) + -1739.166667:
(io203 >= 2711 && io203 <2735)? io203 = ( 0.833333333 * io203) + -1739.166667:
(io203 >= 2735 && io203 <2769)? io203 = ( 0.588235294 * io203) + -1068.823529:
(io203 >= 2769 && io203 <2783)? io203 = ( 1.428571429 * io203) + -3395.714286:
(io203 >= 2783 && io203 <2808)? io203 = ( 0.8 * io203) + -1646.4:
(io203 >= 2808 && io203 <2832)? io203 = ( 0.833333333 * io203) + -1740:
(io203 >= 2832 && io203 <2857)? io203 = ( 0.8 * io203) + -1645.6:
(io203 >= 2857 && io203 <2881)? io203 = ( 0.833333333 * io203) + -1740.833333:
(io203 >= 2881 && io203 <2905)? io203 = ( 0.833333333 * io203) + -1740.833333:
(io203 >= 2905 && io203 <2930)? io203 = ( 0.8 * io203) + -1644:
(io203 >= 2930 && io203 <2956)? io203 = ( 0.769230769 * io203) + -1553.846154:
(io203 >= 2956 && io203 <2978)? io203 = ( 0.909090909 * io203) + -1967.272727:
(io203 >= 2978 && io203 <3003)? io203 = ( 0.8 * io203) + -1642.4:
(io203 >= 3003 && io203 <3028)? io203 = ( 0.8 * io203) + -1642.4:
(io203 >= 3028 && io203 <3054)? io203 = ( 0.769230769 * io203) + -1549.230769:
(io203 >= 3054 && io203 <3079)? io203 = ( 0.8 * io203) + -1643.2:
(io203 >= 3079 && io203 <3105)? io203 = ( 0.769230769 * io203) + -1548.461538:
(io203 >= 3105 && io203 <3132)? io203 = ( 0.740740741 * io203) + -1460:
(io203 >= 3132 && io203 <3159)? io203 = ( 0.740740741 * io203) + -1460:
(io203 >= 3159 && io203 <3188)? io203 = ( 0.689655172 * io203) + -1298.62069:
(io203 >= 3188 && io203 <3218)? io203 = ( 0.666666667 * io203) + -1225.333333:
io203 >= 3218 ? 940:0))/2)

Anton Tananaev2 years ago

Increase the column size in the database.

Victor Kyryllov2 years ago

Anton, thank you very much! Еverything works great!

Ubaid10 months ago

Hi,
I am using FMB920 with fuel sensor
1 > 0 liters
28 = 24 liters
68 = 34 liters
114 = 44 liters
158 = 54 liters
203 = 64 liters

I also increase the size of expression under tc_attributes table using following command.

ALTER TABLE tc_attributes MODIFY expression VARCHAR(10000) NOT NULL

io270 < 28 ? 0:
(io270 >=  1 && io270 < 28 )? io270 = (0.888888888888889 * io270) + -0.888888888888886:
(io270 >=  28 && io270 < 68 )? io270 = (0.25 * io270) + 17:
(io270 >=  68 && io270 < 114 )? io270 = (0.217391304347826 * io270) + 19.2173913043478:
(io270 >=  114 && io270 < 158 )? io270 = (0.227272727272727 * io270) + 18.0909090909091:
(io270 >=  158 && io270 < 203 )? io270 = (0.222222222222222 * io270) + 18.8888888888889:
(io270 >=  203 && io270 < 247 )? io270 = (0.227272727272727 * io270) + 17.8636363636364:

Still getting following error,

org.traccar.handler.ComputedAttributesHandler.computeAttribute:142@9:88 parsing error in ':' - Parsing (ComputedAttributesHandler:142 < AttributeResource:63 < ... < OverrideFilter:49 < ...)

Anton Tananaev10 months ago

I don't think it's a valid expression. You should remove the io270 = assignment.

Ubaid10 months ago

I followed what Victor Kyryllov used,

io270 < 28 ? 0:
(io270 >=  1 && io270 < 28 )? (0.888888888888889 * io270) + -0.888888888888886:
(io270 >=  28 && io270 < 68 )? (0.25 * io270) + 17:
(io270 >=  68 && io270 < 114 )? (0.217391304347826 * io270) + 19.2173913043478:
(io270 >=  114 && io270 < 158 )? (0.227272727272727 * io270) + 18.0909090909091:
(io270 >=  158 && io270 < 203 )? (0.222222222222222 * io270) + 18.8888888888889:
(io270 >=  203 && io270 < 247 )? (0.227272727272727 * io270) + 17.8636363636364:

AND Also,

math:round(io270 < 28 ? 0:
(io270 >=  1 && io270 < 28 )? (0.888888888888889 * io270) + -0.888888888888886:
(io270 >=  28 && io270 < 68 )? (0.25 * io270) + 17:
(io270 >=  68 && io270 < 114 )? (0.217391304347826 * io270) + 19.2173913043478:
(io270 >=  114 && io270 < 158 )? (0.227272727272727 * io270) + 18.0909090909091:
(io270 >=  158 && io270 < 203 )? (0.222222222222222 * io270) + 18.8888888888889:
(io270 >=  203 && io270 < 247 )? (0.227272727272727 * io270) + 17.8636363636364:)

Still showing the following when I click on "Test Expression"

org.traccar.handler.ComputedAttributesHandler.computeAttribute:142@7:80 parsing error in ':' - Parsing (ComputedAttributesHandler:142 < AttributeResource:63 < ... < OverrideFilter:49 < ...)

Anton Tananaev10 months ago

The error is telling you that the expression is invalid. Why do you have a colon at the end of the expression?

Ubaid10 months ago

I tried even the following simple expression

io270 < 1 ? 0
io270 >=  1 && io270 < 28 ? 0.888888888888889 * io270 - 0.888888888888886

still got

org.traccar.handler.ComputedAttributesHandler.computeAttribute:142@2:1 parsing error in 'io270' - Parsing (ComputedAttributesHandler:142 < AttributeResource:63 < ... < OverrideFilter:49 < ...)

Anton Tananaev10 months ago

You should read the syntax documentation before we continue this conversation. What you have in the last example is a complete nonsense.