Is it possible to use a non-linearity table with the MAKE_MOVING macro like you can with the MAKE_NEEDLE macro. I have a non-linear airspeed strip that moves on the x-plane using a mask.

 

Thanks,

Chris

In short - no. You'll need to calculate distance moved based on airspeed e.g. 60-120 knots moves the tape by X pixels, 120-180knots moves the tape by Y pixels, over 180knots moves the tape by Z pixels. Effectively it's a non-linearity table in code!

 

-Dai

Thanks Dai

So using your example would I have to use two different make moving for each range of speeds that have different linearity maybe using a if else logic? Or would I have to code it some other way? Sorry I am very new at this. Mostly did xml, just trying c code now. Appreciate all your help

 

Chris

**

DELETED BY AUTHOR AS UTTERLY USELESS CODE EXAMPLE

**

Sorry Chris - RL isn't leaving me much time to visit any forums ATM. The code block below is for a flap indicator which moves the tape different distances depending on flap angle selected. The theory is exactly the same as an ASI-driven tape. Note the one VERY large gotcha - as you move across 'boundaries' you have to first subtract the previous boundary, then calculate the current position, then finally add that to ALL previous boundaries.

 

if(leftflap_pos<1986)
{
left_curr_pos=leftflap_pos*0.0135;
}
else if(leftflap_pos<4965)
{
// Subtract the previous boundary
left_curr_flaps=leftflap_pos-1985;
// Calculate the current position
left_curr_flaps*=0.0095;
// Add current to previous
left_curr_pos=left_curr_flaps+(1985*0.0135);
}
else if(leftflap_pos<8937)
{
// Subract the previous boundary
left_curr_flaps=leftflap_pos-4964;
// Calculate the current one
left_curr_flaps*=0.0065;
// Add current to all previous
left_curr_pos=left_curr_flaps+(1985*0.0135)+(2979*0.0095);
}
else if(leftflap_pos<10923)
{
// etc.
left_curr_flaps=leftflap_pos-8936;
left_curr_flaps*=0.006;
left_curr_pos=left_curr_flaps+(1985*0.0135)+(2979*0.0095)+(3973*0.0065);
}
else if(leftflap_pos<16385)
{
left_curr_flaps=leftflap_pos-10922;
left_curr_flaps*=0.0047;
left_curr_pos=left_curr_flaps+(1985*0.0135)+(2979*0.0095)+(3973*0.0065)+(1986*0.006);
}

Thanks again Dai,

 

The big gotcha is what I have been trying to figure out. I will look at your code and try to figure it out and post an update. Thanks a lot for your help.

 

Chris

Dai,

 

That was it. Appreciate all you help. Those non-linearity tables are a lot easier in xml! But were is the challenge in that!!!

Good news :smile: I was actually trying to post an edit with a bit more explanation when the broadband went phut! just as I hit save.... :Cry: So here it is anyway - it may help someone else.

 

if(leftflap_pos<1986) // 1986 = 4 degrees
{
left_curr_pos=leftflap_pos*0.0135;
}
else if(leftflap_pos<4965) // 4965 = 10 degrees
{
// Subtract the previous boundary area
left_curr_flaps=leftflap_pos-1985;
// Calculate the current position - trial and error to figure out the tape movement for six degrees (from 4 to 10)
left_curr_flaps*=0.0095;
// Add current to previous
left_curr_pos=left_curr_flaps+(1985*0.0135);
}
else if(leftflap_pos<8937) // 18 degrees
{
// Subract the previous boundary
left_curr_flaps=leftflap_pos-4964;
// Calculate the current position - trial and error to figure out the tape movement for the eight degrees (from 10 to 18)
left_curr_flaps*=0.0065;
// Add current to all previous
left_curr_pos=left_curr_flaps+(1985*0.0135)+(2979*0.0095);
}
else if(leftflap_pos<10923)
{
// etc.
left_curr_flaps=leftflap_pos-8936;
left_curr_flaps*=0.006;
left_curr_pos=left_curr_flaps+(1985*0.0135)+(2979*0.0095)+(3973*0.0065);
}
else if(leftflap_pos<16385)
{
left_curr_flaps=leftflap_pos-10922;
left_curr_flaps*=0.0047;
left_curr_pos=left_curr_flaps+(1985*0.0135)+(2979*0.0095)+(3973*0.0065)+(1986*0.006);
}

yea my tape range was 0-60 for one range and 61-450 for the other. I still ended up breaking the tape down to 0-60, 61-200, 201-300, 301-450 just to get better accuracy. When I left it at 61-450 I lost some accuracy at the end of the range.

 

Chris