Etydhv

I am trying to align my equation number to be vertically centre to the equation. How can I go about doing this? I have attached a screenshot of my output.

I am using pdfLaTex+MakeIndex+BibTeX as me Latex processor if that could possibly make a difference.

Here is my code,

documentclass[a4paper, 11pt, leqno]article
usepackageamsmath
usepackageamsfonts
usepackageindentfirst
usepackagehyperref
usepackagebigints

setlengthparindent0em
setlengthparskip1em

begindocument

par
This is some text.
beginequation labelcyclicFourierTransform
beginsplit
centerline$F(s) = bigints_-infty^infty f(x)e^-i2pixs;mathrmdx$ \
centerline$f(x) = bigints_-infty^infty F(s)e^-i2pixs;mathrmds$
endsplit
endequation

par
This is some more text.

enddocument

And here is my output,

Thank you in advance!

I'd use aligned instead of split and normal ints instead of bigints. Also, as others pointed out, remove centerline and consider not using it in LaTeX at all.

documentclass[a4paper, 11pt, leqno]article
usepackageamsmath
usepackageamsfonts
usepackageindentfirst
usepackagehyperref
usepackagebigints

setlengthparindent0em
setlengthparskip1em

begindocument

This is some text.
beginequation labelcyclicFourierTransform
beginaligned
F(s) &= int_-infty^infty f(x)e^-i2pixs;mathrmdx \
f(x) &= int_-infty^infty F(s)e^-i2pixs;mathrmds
endaligned
endequation

This is some more text.

enddocument

Not sure why you're complicating things.

documentclass[a4paper, 11pt, leqno]article
usepackageamsmath
usepackageamsfonts
usepackageindentfirst
usepackage[skip=1em]parskip
usepackagehyperref

newcommanddiffmathop!mathrmd

begindocument

par
This is some text.
beginequation labelcyclicFourierTransform
beginsplit
F(s) &= int_-infty^infty f(x)e^-i2pixsdiff x \
f(x) &= int_-infty^infty F(s)e^-i2pixsdiff s
endsplit
endequation
This is some more text.

enddocument

Note the better definition for the differential operator (I'd prefer an italic d, though; with this setup, you can change it just once for the whole document).

The parskip package is better if you really want to use vertical space between paragraphs. Again, just commenting out the call to the package allows for switching to traditional typesetting. The package makes also some other fixes that manual setting doesn't perform. I left 1em, but it's not really a good unit to use here.

If you remove centerline you get

documentclass[a4paper, 11pt, leqno]article
usepackageamsmath
usepackageamsfonts
usepackageindentfirst
usepackagehyperref
usepackagebigints

setlengthparindent0em
setlengthparskip1em

begindocument

par
This is some text.
beginequation labelcyclicFourierTransform
beginsplit
F(s) = bigints_-infty^infty f(x)e^-i2pixs;mathrmdx \
f(x) = bigints_-infty^infty F(s)e^-i2pixs;mathrmds
endsplit
endequation

par
This is some more text.

enddocument

Or an arguably cleaner version with inputs from David Carlisle.

documentclass[a4paper, 11pt, leqno]article
usepackageamsmath
usepackageamsfonts
usepackageindentfirst
usepackagehyperref
usepackagebigints

setlengthparindent0em
setlengthparskip1em

begindocument

This is some text.
beginequation labelcyclicFourierTransform
beginsplit
F(s) = intlimits_-infty^infty f(x),mathrme^-mathrmi2pixs,mathrmdx \
f(x) = intlimits_-infty^infty F(s),mathrme^-mathrmi2pixs,mathrmds
endsplit
endequation

This is some more text.

enddocument