Appendix - Rock Magnetic Cyclostratigraphy - page 148

A.3 Command Strings used for Selected Figures

The following command strings reproduce selected figures in the text. The
corresponding plots displayed in Chapters 4 and 5 have been edited for clarity
and aesthetics. The Eocene Arguis Formation datasets that are analyzed,
“ arguisgrain.txt ” and arguisarm.txt from Kodama et al. (2010)
may be downloaded—as well as command strings for the remaining
figures—from:
https://jshare.johnshopkins.edu/lhinnov1/scripts/

Figure 4.2 Staircase interpolation of Arguis grain size stratigraphic series:
Input Arguis Formation grain size series in a two-column array arguisgrain,
with stratigraphic height in column 1 and grain size (integer from 3 = fine to
9 = coarse) in column 2.
dint=0.5;
[stratint,grainint]=staircase(arguisgrain,dint);
figure;plot(stratint,grainint);

Figure 4.3a Assessing the variable sample rate of ARM stratigraphic
series: Input Arguis Formation ARM series is in the two-column array
arguisarm, with stratigraphic height in column 1 and anhysteretic rema-
nent magnetism (ARM) in column 2. These are separated into individual
vectors, strat and arm, and then the first difference of strat is taken to
assess the sample rate.
strat=arguisarm(:,1);
arm=arguisarm(:,2);
len=length(strat);
dstrat=diff(strat);
strat1=strat(1):strat(len-1);
figure;plot(strat1,dstrat);

Figure 4.3b and c Linear interpolation of the ARM stratigraphic series to
the mean sample rate (0.6757 m): Mean sample rate is assessed; series is
interpolated using interp1.m to the mean sample rate; original and interpo-
lated ARM stratigraphic series are plotted together.
dmean=mean(diff(strat));
dintmean=2.8:dmean:795.4;
armdintmean=interp1(strat,arm,dintmean);
figure;plot(strat,arm); hold all; plot(dintmean,
armdintmean);
Figure 4.3d Spline interpolation of the ARM stratigraphic series to a high-
resolution sample rate (0.05 m): A high-resolution sample rate is set at
Δd = 0.05; ARM series is interpolated using interp1.m with the “spline”
option; the original and interpolated ARM stratigraphic series are plotted
together.
dhigh=0.05;
dinthigh=2.8:dhigh:795.4;