ThingspeakRead returns cell array

1 次查看（过去 30 天）
Dimitris Lymperis
Dimitris Lymperis 2020-12-17
移动：Christopher Stapels 2024-1-5
I am using the following commands in a script to retrieve the records from the last 5 minutes of two diffirent temperature sensors.
Temp_1 = thingSpeakRead(readChannelID_1,'Fields',Temperature_1_FieldID,'NumMinutes',5,'ReadKey',readAPIKey_1,'OutputFormat','timetable')
Temp_2 = thingSpeakRead(readChannelID_2,'Fields',Temperature_2_FieldID,'NumMinutes',5,'ReadKey',readAPIKey_2,'OutputFormat','timetable')
Some times i get a good one timetable with double values (rarely) for temperature and some other time i get a cell array with the following format.
Timestamps Temperature_2
____________________ _____________
17-Dec-2020 23:16:00 {'nan' }
17-Dec-2020 23:16:16 {'16.10000'}
17-Dec-2020 23:16:31 {'16.10000'}
17-Dec-2020 23:18:52 {'16.10000'}
17-Dec-2020 23:19:09 {'nan' }
17-Dec-2020 23:19:25 {'16.10000'}
17-Dec-2020 23:19:41 {'16.10000'}
17-Dec-2020 23:20:28 {'16.10000'}
17-Dec-2020 23:20:44 {'16.10000'}
why does it happen and how can i get only the double values?

请先登录，再回答此问题。

回答（1 个）

Christopher Stapels
Christopher Stapels 2020-12-21
移动：Christopher Stapels 2024-1-5
thingSpeakRead is returning a cell array when there is text in the fields. When you are reading the 'nan' values, ThingSpeak is giving you a cell array. Try reading a section where there are no 'nan' values.
Are you writing to the same channel with two different devices? If so, that would explain the empty entries. We reccomend one channel per device.
By the way, you can read both fields at once if you use 'fields', [Temperature_1_FieldID Temperature_2_FieldID].

社区

更多回答在  ThingSpeak Community

类别

在 Help Center 和 File Exchange 中查找有关 Visualize Data 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by