# Displaying FFT Analysis with xy Graph

**URL:** <https://community.grafana.com/t/displaying-fft-analysis-with-xy-graph/88698>\
**Category:** InfluxDB\
**Created:** [May 31, 2023, 2:47pm UTC](https://community.grafana.com/t/displaying-fft-analysis-with-xy-graph/88698 "2023-05-31T14:47:28Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![marianutz](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@marianutz](https://community.grafana.com/u/marianutz)\
**Post date:** [May 31, 2023, 2:47pm UTC](https://community.grafana.com/t/displaying-fft-analysis-with-xy-graph/88698/1 "2023-05-31T14:47:28Z")

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- What Grafana version and what operating system are you using?  
I’m working with Grafana V9.4.7 on Windows 10

- **What** are you trying to achieve?  
I want to display a FFT Analysis with Grafana. The Analysis is done within a python script. I transfer the results with MQTT to InfluxDB.

- **How** are you trying to achieve it?  
I tried to transfer the data in different formats:

1. Two different topics for the frequency and the magnitude. I can display the values in grafana with mqtt\_consumer.
2. One topic for both values in the following format: FFT = {“frequency”: 0.0, “magnitude”: 1.9435151515151514}. Grafana tells me “No data”
3. One topic for both values in the following format: FFT = [62.5, 0.0026666666666664805]. Grafana tells me “No data”

This is my query: SELECT mean(“value”) FROM “mqtt\_consumer” WHERE (“topic” = ‘SENS/Measurements/MPU/FFT’) AND $timeFilter GROUP BY time($\_\_interval) fill(null)

- What happened?  
The connection should be not the problem because I can receive the same topics for the first case. But I can’t display them with a table or a xy graph.

- What did you **expect** to happen?  
I expected in the second case, that I can see a table in this format:  
| Timestamp | Frequency | Magnitude |

- Can you copy/paste the configuration(s) that you are having problems with?  
This is my query and also most likely my only configuration: SELECT mean(“value”) FROM “mqtt\_consumer” WHERE (“topic” = ‘SENS/Measurements/MPU/FFT’) AND $timeFilter GROUP BY time($\_\_interval) fill(null)  
There are no more configurations with the xy Graph because I already can’t display the data with a table.

- Did you receive any errors in the Grafana UI or in related logs? If so, please tell us **exactly** what they were.  
No, I don’t receive any error messages.

- Did you follow any online instructions? If so, what is the URL?  
I’m really new to Grafana and have some issues with finding easy documentation for me as a beginner for this exact subject. Hopefully the community can help me. Please tell me if any important information is missing. Thank you very much!

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**Author:** ![yosiasz](https://sea2.discourse-cdn.com/grafana/user_avatar/community.grafana.com/yosiasz/32/45847_2.png) [@yosiasz](https://community.grafana.com/u/yosiasz)\
**Post date:** [May 31, 2023, 4:04pm UTC](https://community.grafana.com/t/displaying-fft-analysis-with-xy-graph/88698/2 "2023-05-31T16:04:36Z")

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Welcome @marianutz

is the data in value column literally either

FFT = {“frequency”: 0.0, “magnitude”: 1.9435151515151514}

or

FFT = [62.5, 0.0026666666666664805]

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<div class="post-metadata">

**Author:** ![marianutz](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@marianutz](https://community.grafana.com/u/marianutz)\
**Post date:** [June 1, 2023, 6:14am UTC](https://community.grafana.com/t/displaying-fft-analysis-with-xy-graph/88698/3 "2023-06-01T06:14:20Z")

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Hi @yosiasz

Thank you for your reply!

the MQTT Broker receives both formats at the moment. (The exact topics are …/MPU/FFT and …/test/FFT.) But I can see none of them in Grafana in coumns.