# Perspective XY Chart: Logarithmic value axis cannot have values \<= 0

**URL:** <https://forum.inductiveautomation.com/t/perspective-xy-chart-logarithmic-value-axis-cannot-have-values-0/97561>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [October 21, 2024, 7:06pm UTC](https://forum.inductiveautomation.com/t/perspective-xy-chart-logarithmic-value-axis-cannot-have-values-0/97561 "2024-10-21T19:06:22Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tony\_Phung](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@Tony\_Phung](https://forum.inductiveautomation.com/u/Tony_Phung)\
**Post date:** [October 21, 2024, 7:06pm UTC](https://forum.inductiveautomation.com/t/perspective-xy-chart-logarithmic-value-axis-cannot-have-values-0/97561/1 "2024-10-21T19:06:22Z")

</div>

I am working on a perspective project where I am using an XY chart to display some data to the end user. The data is coming from my tag historian set up on some tags that are outputting very small numeric values (we're talking about values down in the 1E-12 to 1E-13 range). I know that leaving the min and max values in the y-axis section of an XY chart lets the chart auto determine what should be the min and max values for displaying your data:

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/8/48a2517ca7e1afbc5c4f376116cb2fe5b6def143.png)

But whenever I check the logarithmic property, I get the following error:

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/2/326e3b436c57a0be27ed00fabc231a9795980ca6.png)

Could someone explain why this is happening and what to do to address this issue? I'm guessing it has to do with my data source and that there are null values or negative values in my datasource.

---

<div class="post-metadata">

**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [October 21, 2024, 7:29pm UTC](https://forum.inductiveautomation.com/t/perspective-xy-chart-logarithmic-value-axis-cannot-have-values-0/97561/2 "2024-10-21T19:29:29Z")

</div>

1. As a matter of interest, why have you got a binding on `yAxes.0.value.logarithmic`?
2. Can you post the chart's dataSource here so we can try it out? See [Wiki - how to post code on this forum](https://forum.inductiveautomation.com/t/wiki-how-to-post-code-on-this-forum/77831) if required.

---

<div class="post-metadata">

**Author:** ![Tony\_Phung](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@Tony\_Phung](https://forum.inductiveautomation.com/u/Tony_Phung)\
**Post date:** [October 21, 2024, 7:47pm UTC](https://forum.inductiveautomation.com/t/perspective-xy-chart-logarithmic-value-axis-cannot-have-values-0/97561/3 "2024-10-21T19:47:10Z")

</div>

1. I have a binding on `yAxes.0.value.logarithmic` to allow the end user to toggle between linear scale and logarithmic scale.
2. My apologies if this is in the incorrect format, here is my datasource:

```python
{
  "data": [
    {
      "t_stamp": 1729537394789,
      "Series3": 9.999999960041972e-13,
      "Series4": 2.4500000552624135e-12
    },
    {
      "t_stamp": 1729537396589,
      "Series3": 9.999999960041972e-13,
      "Series4": 2.4500000552624135e-12
    },
    {
      "t_stamp": 1729537398389,
      "Series3": -6.939999790123164e-13,
      "Series4": 1.6600000454086716e-12
    },
    {
      "t_stamp": 1729537400189,
      "Series3": -6.939999790123164e-13,
      "Series4": 1.6600000454086716e-12
    },
    {
      "t_stamp": 1729537401989,
      "Series3": 2.560000009286384e-13,
      "Series4": 3.6299999464639576e-12
    },
    {
      "t_stamp": 1729537403789,
      "Series3": 2.560000009286384e-13,
      "Series4": 3.6299999464639576e-12
    },
    {
      "t_stamp": 1729537405589,
      "Series3": 1.8399999406060186e-12,
      "Series4": 3.0699999833960767e-12
    },
    {
      "t_stamp": 1729537407389,
      "Series3": 1.8399999406060186e-12,
      "Series4": 3.0699999833960767e-12
    },
    {
      "t_stamp": 1729537409189,
      "Series3": 4.019999936231977e-13,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537410989,
      "Series3": 4.019999936231977e-13,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537412789,
      "Series3": 4.019999936231977e-13,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537414589,
      "Series3": 1.3899999857722167e-12,
      "Series4": 3.520000046650096e-12
    },
    {
      "t_stamp": 1729537416389,
      "Series3": 1.3899999857722167e-12,
      "Series4": 3.520000046650096e-12
    },
    {
      "t_stamp": 1729537418189,
      "Series3": 6.389999748952768e-13,
      "Series4": 4.440000016953105e-12
    },
    {
      "t_stamp": 1729537419989,
      "Series3": 6.389999748952768e-13,
      "Series4": 4.440000016953105e-12
    },
    {
      "t_stamp": 1729537421789,
      "Series3": 1.3300000207064344e-12,
      "Series4": 3.0100000183302944e-12
    },
    {
      "t_stamp": 1729537423589,
      "Series3": 1.3300000207064344e-12,
      "Series4": 3.0100000183302944e-12
    },
    {
      "t_stamp": 1729537425389,
      "Series3": 1.3300000207064344e-12,
      "Series4": 3.0100000183302944e-12
    },
    {
      "t_stamp": 1729537427189,
      "Series3": 5.840000249883459e-13,
      "Series4": 2.5900000460293837e-12
    },
    {
      "t_stamp": 1729537428989,
      "Series3": 6.570000077830984e-13,
      "Series4": 4.729999811964314e-12
    },
    {
      "t_stamp": 1729537430789,
      "Series3": 6.570000077830984e-13,
      "Series4": 4.729999811964314e-12
    },
    {
      "t_stamp": 1729537432589,
      "Series3": 6.570000077830984e-13,
      "Series4": 4.729999811964314e-12
    },
    {
      "t_stamp": 1729537434389,
      "Series3": 6.570000077830984e-13,
      "Series4": 1.860000001241424e-12
    },
    {
      "t_stamp": 1729537436189,
      "Series3": 6.570000077830984e-13,
      "Series4": 1.860000001241424e-12
    },
    {
      "t_stamp": 1729537437989,
      "Series3": 1.1100000042382763e-12,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537439789,
      "Series3": 1.1100000042382763e-12,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537441589,
      "Series3": -2.0099999681159886e-13,
      "Series4": 2.569999985393978e-12
    },
    {
      "t_stamp": 1729537443389,
      "Series3": -2.0099999681159886e-13,
      "Series4": 2.569999985393978e-12
    },
    {
      "t_stamp": 1729537445189,
      "Series3": 1.3700000335570284e-12,
      "Series4": 4.0900000400356795e-12
    },
    {
      "t_stamp": 1729537446989,
      "Series3": 1.3700000335570284e-12,
      "Series4": 4.0900000400356795e-12
    },
    {
      "t_stamp": 1729537448789,
      "Series3": 1.3700000335570284e-12,
      "Series4": 4.0900000400356795e-12
    },
    {
      "t_stamp": 1729537450589,
      "Series3": 1.1299999564534646e-12,
      "Series4": 2.569999985393978e-12
    },
    {
      "t_stamp": 1729537452389,
      "Series3": 1.1299999564534646e-12,
      "Series4": 2.569999985393978e-12
    },
    {
      "t_stamp": 1729537454189,
      "Series3": 1.0400000088547912e-12,
      "Series4": 2.759999910909028e-12
    },
    {
      "t_stamp": 1729537455989,
      "Series3": 1.0400000088547912e-12,
      "Series4": 2.759999910909028e-12
    },
    {
      "t_stamp": 1729537457789,
      "Series3": 9.670000260600387e-13,
      "Series4": 2.5399998944408697e-12
    },
    {
      "t_stamp": 1729537459589,
      "Series3": 9.670000260600387e-13,
      "Series4": 2.5399998944408697e-12
    },
    {
      "t_stamp": 1729537461389,
      "Series3": 9.130000087117368e-14,
      "Series4": 3.209999974163047e-12
    },
    {
      "t_stamp": 1729537463189,
      "Series3": 9.130000087117368e-14,
      "Series4": 3.209999974163047e-12
    },
    {
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    },
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      "Series3": 1.3700000335570284e-12,
      "Series4": 3.0300000789657e-12
    },
    {
      "t_stamp": 1729537468589,
      "Series3": 1.3700000335570284e-12,
      "Series4": 3.0300000789657e-12
    },
    {
      "t_stamp": 1729537470389,
      "Series3": 1.5500000371745926e-12,
      "Series4": 3.6000000723512837e-12
    },
    {
      "t_stamp": 1729537472189,
      "Series3": 1.5500000371745926e-12,
      "Series4": 3.6000000723512837e-12
    },
    {
      "t_stamp": 1729537473989,
      "Series3": 1.1100000042382763e-12,
      "Series4": 2.189999917523444e-12
    },
    {
      "t_stamp": 1729537475789,
      "Series3": 1.1100000042382763e-12,
      "Series4": 2.189999917523444e-12
    },
    {
      "t_stamp": 1729537477589,
      "Series3": -9.860000186115436e-13,
      "Series4": 3.1899999135276413e-12
    },
    {
      "t_stamp": 1729537479389,
      "Series3": -9.860000186115436e-13,
      "Series4": 3.1899999135276413e-12
    },
    {
      "t_stamp": 1729537481189,
      "Series3": -9.860000186115436e-13,
      "Series4": 3.1899999135276413e-12
    },
    {
      "t_stamp": 1729537482989,
      "Series3": 1.100000014578155e-13,
      "Series4": 2.8499999669279186e-12
    },
    {
      "t_stamp": 1729537484789,
      "Series3": 1.100000014578155e-13,
      "Series4": 2.8499999669279186e-12
    },
    {
      "t_stamp": 1729537486589,
      "Series3": 1.5500000371745926e-12,
      "Series4": 3.209999974163047e-12
    },
    {
      "t_stamp": 1729537488389,
      "Series3": 1.5500000371745926e-12,
      "Series4": 3.209999974163047e-12
    },
    {
      "t_stamp": 1729537490189,
      "Series3": 8.21000006260425e-13,
      "Series4": 3.780000184389065e-12
    },
    {
      "t_stamp": 1729537491989,
      "Series3": 8.21000006260425e-13,
      "Series4": 3.780000184389065e-12
    },
    {
      "t_stamp": 1729537493789,
      "Series3": 2.9200001249417296e-13,
      "Series4": 2.2300000387942553e-12
    },
    {
      "t_stamp": 1729537495589,
      "Series3": 2.9200001249417296e-13,
      "Series4": 2.2300000387942553e-12
    },
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      "t_stamp": 1729537497389,
      "Series3": 1.639999984773266e-12,
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    },
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      "Series4": 2.320000094813146e-12
    },
    {
      "t_stamp": 1729537500989,
      "Series3": 1.639999984773266e-12,
      "Series4": 2.320000094813146e-12
    },
    {
      "t_stamp": 1729537502789,
      "Series3": 1.0599999610699795e-12,
      "Series4": 1.4599999811557018e-12
    },
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      "t_stamp": 1729537504589,
      "Series3": 1.0599999610699795e-12,
      "Series4": 1.4599999811557018e-12
    },
    {
      "t_stamp": 1729537506389,
      "Series3": 4.559999838664452e-13,
      "Series4": 2.34999996892582e-12
    },
    {
      "t_stamp": 1729537508189,
      "Series3": 4.559999838664452e-13,
      "Series4": 2.34999996892582e-12
    },
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      "t_stamp": 1729537509989,
      "Series3": -2.560000009286384e-13,
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      "t_stamp": 1729537511789,
      "Series3": -2.560000009286384e-13,
      "Series4": 3.4899999556969874e-12
    },
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      "t_stamp": 1729537513589,
      "Series3": -2.560000009286384e-13,
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    },
    {
      "t_stamp": 1729537515389,
      "Series3": 7.670000160171775e-13,
      "Series4": 2.870000027563324e-12
    },
    {
      "t_stamp": 1729537517189,
      "Series3": -1.8300000458135873e-13,
      "Series4": 3.1600000394149674e-12
    },
    {
      "t_stamp": 1729537518989,
      "Series3": -1.8300000458135873e-13,
      "Series4": 3.1600000394149674e-12
    },
    {
      "t_stamp": 1729537520789,
      "Series3": -1.8300000458135873e-13,
      "Series4": 3.1600000394149674e-12
    },
    {
      "t_stamp": 1729537522589,
      "Series3": -9.48999993172217e-13,
      "Series4": -3.6499999528892546e-13
    },
    {
      "t_stamp": 1729537524389,
      "Series3": -9.48999993172217e-13,
      "Series4": -3.6499999528892546e-13
    },
    {
      "t_stamp": 1729537526189,
      "Series3": -2.1900000259436614e-13,
      "Series4": 2.810000062497542e-12
    },
    {
      "t_stamp": 1729537527989,
      "Series3": -2.1900000259436614e-13,
      "Series4": 2.810000062497542e-12
    },
    {
      "t_stamp": 1729537529789,
      "Series3": 5.480000134228113e-13,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537531589,
      "Series3": 5.480000134228113e-13,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537533389,
      "Series3": 5.480000134228113e-13,
      "Series4": 3.3999998996780967e-12
    },
    {
      "t_stamp": 1729537535189,
      "Series3": 8.760000103774646e-13,
      "Series4": 2.0599999570741767e-12
    },
    {
      "t_stamp": 1729537536989,
      "Series3": 5.109999879834848e-13,
      "Series4": 5.220000213329579e-12
    },
    {
      "t_stamp": 1729537538789,
      "Series3": 5.109999879834848e-13,
      "Series4": 5.220000213329579e-12
    },
    {
      "t_stamp": 1729537540589,
      "Series3": 5.109999879834848e-13,
      "Series4": 5.220000213329579e-12
    },
    {
      "t_stamp": 1729537542389,
      "Series3": 9.309999602843955e-13,
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    },
    {
      "t_stamp": 1729537544189,
      "Series3": 9.309999602843955e-13,
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    },
    {
      "t_stamp": 1729537545989,
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    {
      "t_stamp": 1729537547789,
      "Series3": 1.67999999762386e-12,
      "Series4": 2.0599999570741767e-12
    },
    {
      "t_stamp": 1729537549589,
      "Series3": 3.099999911718859e-13,
      "Series4": 3.520000046650096e-12
    },
    {
      "t_stamp": 1729537551389,
      "Series3": 3.099999911718859e-13,
      "Series4": 3.520000046650096e-12
    },
    {
      "t_stamp": 1729537553189,
      "Series3": 1.4800000417911074e-12,
      "Series4": 2.499999990010493e-12
    },
    {
      "t_stamp": 1729537554989,
      "Series3": 1.4800000417911074e-12,
      "Series4": 2.499999990010493e-12
    },
    {
      "t_stamp": 1729537556789,
      "Series3": 1.4800000417911074e-12,
      "Series4": 2.499999990010493e-12
    },
    {
      "t_stamp": 1729537558589,
      "Series3": 1.8300000458135873e-13,
      "Series4": 3.810000058501739e-12
    },
    {
      "t_stamp": 1729537560389,
      "Series3": 1.8300000458135873e-13,
      "Series4": 3.810000058501739e-12
    },
    {
      "t_stamp": 1729537562189,
      "Series3": 2.7699999412267307e-12,
      "Series4": 2.2099999781588497e-12
    },
    {
      "t_stamp": 1729537563989,
      "Series3": 2.7699999412267307e-12,
      "Series4": 2.2099999781588497e-12
    },
    {
      "t_stamp": 1729537565789,
      "Series3": -4.19999999405965e-13,
      "Series4": 5.589999817201541e-12
    },
    {
      "t_stamp": 1729537567589,
      "Series3": -4.19999999405965e-13,
      "Series4": 5.589999817201541e-12
    },
    {
      "t_stamp": 1729537569389,
      "Series3": -9.130000358167911e-13,
      "Series4": 2.660000041412869e-12
    },
    {
      "t_stamp": 1729537571189,
      "Series3": -9.130000358167911e-13,
      "Series4": 2.660000041412869e-12
    },
    {
      "t_stamp": 1729537572989,
      "Series3": -9.130000358167911e-13,
      "Series4": 2.660000041412869e-12
    }
  ]
}

```

---

<div class="post-metadata">

**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [October 21, 2024, 8:01pm UTC](https://forum.inductiveautomation.com/t/perspective-xy-chart-logarithmic-value-axis-cannot-have-values-0/97561/4 "2024-10-21T20:01:40Z")

</div>

> [@Tony\_Phung](#):
>
> ```python
> {
> "data": [
> {
> "t_stamp": 1729537394789,
> "Series3": 9.999999960041972e-13,
> "Series4": 2.4500000552624135e-12
> },
> {
> "t_stamp": 1729537396589,
> "Series3": 9.999999960041972e-13,
> "Series4": 2.4500000552624135e-12
> },
> {
> "t_stamp": 1729537398389,
> "Series3": -6.939999790123164e-13, <<< negative number!
> "Series4": 1.6600000454086716e-12
> },
> {
> "t_stamp": 1729537400189,
> "Series3": -6.939999790123164e-13, <<< negative number!
> "Series4": 1.6600000454086716e-12
> ,,,
> 
> ```

Isn't the problem that you're asking the chart to get the log of a negative number?  
Thought experiment: what value of _ **x** _ in 10_ **x** _ will give you a negative result?

More here:

> **[Why can't logarithms be negative? — Krista King Math | Online math help](https://www.kristakingmath.com/blog/why-cant-logarithms-be-negative)**
>
> The only numbers you can plug into a logarithm are positive numbers not equal to 1.