URL:
<http://gna.org/support/?3138>
Summary: Interpolating theta through spin-lock offset
[Omega], rather than spin-lock field strength [w1]
Project: relax
Submitted by: tlinnet
Submitted on: Fri 21 Mar 2014 10:57:24 AM UTC
Category: Feature request
Priority: 5 - Normal
Severity: 1 - Wish
Status: Postponed
Assigned to: None
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Operating System: None
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Details:
When making a graph of R1_rho as function of theta, the current setup in relax
is by interpolating R1_rho points by extending the dispersion points
(spin-lock field strength [w1]), and back-calculate the the R1_rho via the
used model function.
This can lead to some spurious graphs, which have been attached.
ramp_w1_ramping_spin-lock_field_strength.png
The contribution from Rex: sin^2(t)*(phi_ex*kex/(kex^2+w_e^2)) when ramping
w_1, leads to some "shoulders", which can lead to a conclusion of wrong
input.
Simpler graphs would be expected, if ramping spin-lock offset [Omega]
instead.
See attached
ramp_Omega_spin-lock_offset.png
The graphs are also available at:
http://wiki.nmr-relax.com/DPL94_math
The code that needs to be modified resides in:
specific_analyses.relax_disp.optimisation.optimisation.back_calc_r2eff(spin=cdp.fakespin,
spin_id=fake_spin_inte, spin_lock_nu1=spin_lock_nu1)
# Which calls
specific_analyses.relax_disp.disp_data.return_offset_data()
chemical_shifts, offsets, tilt_angles, Delta_omega, w_eff =
return_offset_data(spins=[spin], spin_ids=[spin_id], field_count=field_count,
fields=spin_lock_nu1)
These should be modified to accept interpolated offset data.
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File Attachments:
-------------------------------------------------------
Date: Fri 21 Mar 2014 10:57:24 AM UTC Name:
ramp_w1_ramping_spin-lock_field_strength.png Size: 26kB By: tlinnet
<http://gna.org/support/download.php?file_id=20395>
-------------------------------------------------------
Date: Fri 21 Mar 2014 10:57:24 AM UTC Name: math.png Size: 10kB By:
tlinnet
<http://gna.org/support/download.php?file_id=20396>
-------------------------------------------------------
Date: Fri 21 Mar 2014 10:57:24 AM UTC Name: ramp_Omega_spin-lock_offset.png
Size: 26kB By: tlinnet
<http://gna.org/support/download.php?file_id=20397>
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[sr #3138] Interpolating theta through spin-lock offset [Omega], rather than spin-lock field strength [w1]