从模板代码创建MATLAB分析脚本

To calculate the maximum and minimum daily temperatures from the Natick weather station, write a MATLAB® script using the code template provided.

去Appstab in ThingSpeak and selectMATLAB分析。ClickNew中,选择Calculate high and low temperatures, and click创造。

Analyze Your Data

这MATLAB Codefield is prepopulated with code to calculate the maximum and minimum temperatures over the past 24 hours.

1) Set the variables for communicating with ThingSpeak. ThereadChannelIDis the channel ID for the public channel that collects data from the weather station. ThetemperatureFieldIDis the field in the channel that contains temperature values. Assign a value to readAPIkey only if you are reading data from a private channel. The weather station is public, so for this example, do not set readAPIkey.

ReadChannelId = 12397;温度fieldid = 4;ReadApikey ='';

2）使用过去24小时读取温度值things peakreadfunction.

[tempF,timeStamp] = thingSpeakRead(readChannelID,'Fields',temperatureFieldID,'numDays',1,'ReadKey',readAPIKey);

3) Calculate the maximum and minimum temperatures in Fahrenheit usingmax和min。这n, identify the corresponding timestamps and display the results.

[maxTempF,maxTempIndex] = max(tempF); [minTempF,minTempIndex] = min(tempF); timeMaxTemp = timeStamp(maxTempIndex); timeMinTemp = timeStamp(minTempIndex); display(maxTempF,'Maximum temperature for the past 24 hours is');

102

display(minTempF,'Minimum temperature for the past 24 hours is');

81

4) Execute your code by clicking保存并运行。这Output字段显示您的结果。

Write Data to a Channel

1) Store your maximum or minimum temperature calculation result by writing it to a private channel. To create a ThingSpeak channel, go to theChannelstab and selectMy Channels。ClickNew Channel。Select the corresponding check box, and enter these channel setting values:

ClickSave Channel。

2) In theMATLAB Codefield, set the variables for writing to your private channel. Replace the given values forwriteChannelID和Writeapikeywith your values. You can find the channel ID and write API key in theChannel Info页面右侧的面板。

% Replace with the ID of the channel to write data to.writeChannelID = 17504;% Enter the write API key between the ''.Writeapikey='23zlgobbu9twhg2h';

3) Uncomment the following line to write the maximum temperature reading to your channel. To save the minimum temperature value, changemaxTempFtominTempF。

％thingspeakwrite（Writechannelid，maxtempf，'timestamp'，timemaxtemp，'writekey'，writeapikey）;

4) Execute your code by clicking保存并运行。这chart in your ThingSpeak channel is populated with a single point representing the maximum temperature reading at the time when it was recorded. You can access your channel by clicking the channel link in theChannel Info页面右侧的面板。