'pow' was not declared in this scope

Troubleshooting
1

I have purchased a GA1A12S202 Log-scale Analog Light Sensor from Adafruit and I am following the tutorial to get it setup, making modifications if required for the Spark Core.

The example contains the following function:

float RawToLux(int raw) {
    float logLux = raw * logRange / rawRange;
    return pow(10, logLux);
}

When using it I am am unable to compile due to the following error:

/nimbus.cpp:103:26: error: 'pow' was not declared in this scope

I was under the impression that the pow function is available as part of the Spark Core so I am a little confused as to why it is not working.

2

@scottsweb, you need to add #include <math.h> to your file. This is an odd one and we are working to get that included as part of “application.h”. :smile:

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3

Perfect. That has done the trick.

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4

Sorry for kicking this up, but I came across this error. Including #include <math.h> to my file works out fine. However almost 1,5 year later pow doesn’t seem to be part of “application.h”, so maybe you can still add it?

5

That sounds odd, but you can still add #include <math.h>
But I might file a PR right now :wink: - or not @mdma :sunglasses:

6

Is it included by default in Arduino? I’m really on the fence here about whether it should be included by default or not. We don’t include a lot of other standard library headers by default, but equally I can see this might be useful.

The danger with including headers that weren’t included before is breaking existing libraries.

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7

@mdma, it is NOT included by default in Arduino! I would not change anything and keep it separate IMO. :wink:

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