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Calculate area of sector
A=function(r,seta) r is radius of sector, seta is angle of sector, and A is its area. Area of sector A is defined as 0.5*(r^2...

1 month ago

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Rounding off numbers to n decimals
Inspired by a mistake in one of the problems I created, I created this problem where you have to round off a floating point numb...

1 month ago

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intersection of matrices
Given two matrices filled with ones and zeros, determine if they share a common row, column entry. These matrices are of identic...

1 month ago

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Check if number exists in vector
Return 1 if number _a_ exists in vector _b_ otherwise return 0. a = 3; b = [1,2,4]; Returns 0. a = 3; b = [1,...

1 month ago

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Return unique values without sorting
If the input vector A is [42 1 1], the output value B must be the unique values [42 1] The values of B are in the same order a...

1 month ago

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Generate N equally spaced intervals between -L and L
Given N and L, return a list of numbers (in ascending order) that divides the interval [-L L] into N equal-length segments. F...

1 month ago

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I want to display negative temperature on channel view
Here are a few ways to get negative numbers into ThingSpeak or to plot them in MATLAB. https://api.thingspeak.com/update?api_ke...

1 month ago | 0

Solved

Getting the indices from a matrix
Inspired by Problem 645. Getting the indices from a matrix. Given a matrix A (or a vector), return the indices (always in row...

1 month ago

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Is thingspeak free version account expire after one year
See the licensing FAQ. Free ThingSpeak licenses will renew yearly in the month you created the license assuming you meet the log...

2 months ago | 0

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Matlab Basics - Rounding III
Write a script to round a large number to the nearest 10,000 e.g. x = 12,358,466,243 --> y = 12,358,470,000

2 months ago

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Matlab Basics - Rounding II
Write a script to round a variable x to 3 decimal places: e.g. x = 2.3456 --> y = 2.346

2 months ago

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Check that number is whole number
Check that number is whole number Say x=15, then answer is 1. x=15.2 , then answer is 0. http://en.wikipedia.org/wiki/Whole_numb...

2 months ago

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MATLAB Basic: rounding IV
Do rounding towards plus infinity. Example: -8.8, answer -8 +8.1 answer 9 +8.50 answer 9

2 months ago

Solved

MATLAB Basic: rounding III
Do rounding towards minus infinity. Example: -8.8, answer -9 +8.1 answer 8 +8.50 answer 8

2 months ago

Solved

MATLAB Basic: rounding II
Do rounding nearest integer. Example: -8.8, answer -9 +8.1 answer 8 +8.50 answer 9

2 months ago

Solved

MATLAB Basic: rounding
Do rounding near to zero Example: -8.8, answer -8 +8.1 answer 8

2 months ago

Answered
App designer table handling
Thanks for showing the result Karol. Im taking your solution and adding it to the answers to help others find it. Solved by ...

2 months ago | 0

Answered
Can't send data to Thingspeak from Microbit DFRobot kit
Are you able to update the channel using the GET command in your browser address bar? Click on your channel view and use the A...

2 months ago | 0

Answered
Unable to write data by bulk update *csv method [ESP8266, Arduino framework]
I havent tested this recently, but I found it in an old folder and I expect that it works. I had to escape some values. Please ...

2 months ago | 0

Answered
Unable to write data by bulk update *csv method [ESP8266, Arduino framework]
The arduino client should take care of url encoding your data. I would use the raw text in the value of char csv_feed Perhap...

3 months ago | 0

Answered
How can I upload and plot temperature values that are both above zero (e.g., ambient) and below zero (e.g., in a freezer)?
I think the library answer seems best. Here is an example using the dallas one wire (that has some other dependancies built in ...

3 months ago | 0

Answered
Will generating an alert API key reset the USER API key?
The alert API key and user API key are seperate. Genenrating an alert API key wil not change your user API key.

3 months ago | 0

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Answered
How to check DataPlugin in MATLAB
This pagedesribes how you can read MATLAB files into labview witha dataplugin and this answer describes some ways to import l...

3 months ago | 0

Answered
HOW TO CLEAN NULL FROM MY GET QUERY
We reccomend using multiple channels to record your data in the case of multiple devices or sensors with different frequencies. ...

3 months ago | 0

Answered
ThingSpeak Channel stopped receiving data since April 13th 2022
We strongly reccomend using the thingSpeak library for arduino and esp if possible. I dont see the problem directly. I would r...

3 months ago | 0

Answered
Why arduino send data to thingspeak only once?
Your device will continue to send data once disconnected from the USB port, as long as it is powered and within the WiFi range. ...

3 months ago | 0

Answered
Thingspeak REST API READ results in data from wrong timezone
Check out the timezone and offset parameters in the read data endpoint.

4 months ago | 0

Answered
MQTT via esp8266 suddenly stopped connecting giving mqttClient.state() = -2 error!?
ThingSpeak recently updated the security certificate. Can you try reprogamming with the new cert? The ESP8266 MQTT example co...

4 months ago | 0

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Answered
In thingspeak , how can I visualize two or more channels on one page so I can view different fields from different nodes at a time ?
In the tabs on the top of the ThingSpeak site, Click on Apps > MATLAB Visualizations then click the green 'New' button, and you ...

4 months ago | 1

Answered
The graph couldn't be seen on the chart although the code ha been run correctly
We strongly reccomend using the ThingSpeak library for arduino, it takes care of a lot of code issues for you. Troubleshooting ...

4 months ago | 0

| accepted