Understanding the resolution on calculating the isotopic distribution function 'isotopicdist.m'

Hello,

I am trying to understand the resolution setting on 'isotopicdist.m' function. In the HELP page regarding the resolution value, it shows:

"ResolutionValue

Value in daltons specifying the approximate resolution of the instrument, given as the Gaussian width at full width half height (FWHH).

Default: 1/16 Da"

However inside the function itself, at line 543 it described:

"w = 1/8; % Width of the Gaussian pulse (in Daltons), usually this value should match the resolution of the instrument."

Are they talking about the same thing? If I want to edit the resolution, is value w the one I should change? What's the differencies between this instrument resolution w and resolution calculated based on R=M/FWHH, where M is m/z.

Many thanks

XY

Answer 1

[Anmol Dhiman]

Hi XiaoYing,

In the above case both w and the ResolutionValue are same. It specifies the approximate resolution of the instrument, given as the Gaussian width (in daltons) at full width at half height (FWHH).

You can change the above value by passing a name-value as shown below while passing the function. w in code will update accordingly.

isotopicdist(..., 'Resolution', ResolutionValue, ...)

You can replace "ResolutionValue" with the amount that you want to set.

Regarding the default value for resolution, I have brought this issue to the notice of our developers. They will investigate the matter further.

I suggest you to provide the ResolutionValue as shown above.

Thanks

Anmol Dhiman

[XiaoYing Wang]

Thank you Anmol!

XiaoYing