A Matlab notebook primer#
Created: 2017-03-30
This notebook is not tested in our CIs and require some extra configuration from the users. You'll need to install octave and the t_tide toolbox.
A common misconception is that Jupyter notebooks are for Python only.
We already showed how to use the
R language,
and now we are going to create a Matlab/Octave toolboxes notebook.
The IOOS conda
environment
installs oct2py, the dependency needed to run Matlab/Octave notebooks.
However, unlike R that can be installed with conda,
we cannot install Matlab or Octave with it.
This notebook relies on system installation of octave but it is possible to run the same on Matlab with very little modification.
Here are some basic Matlab-like array creation and dot multiplication.
x = [1, 2, 3]
y = [1; 2; 3]
z = x*y
x =
1 2 3
y =
1
2
3
z = 14
And a simple plot.
x = linspace(0, 2*pi, 100);
y = sin(x);
plot(x, y)
To demonstrate the Matlab/Octave notebook we will use a well known toolbox for tidal analysis t_tide.
First we need to add it to the path.
addpath(genpath('t_tide_v1.3beta'))
If you are running this on octave you need to load the signal package.
This step is not necessary on Matlab.
pkg load signal;
t_demo is a built-in script that contains a short example of capabilities of tidal analysis toolbox.
t_demo
+ echo ('on')
+ ## Load the example.
+ load ('t_example')
warning: load: file found in load path
+ ## Define inference parameters.
+ infername = ['P1'; 'K2'];
+ inferfrom = ['K1'; 'S2'];
+ infamp = [.33093; .27215];
+ infphase = [-7.07; -22.40];
+ ## The call (see t_demo code for details).
+ ## hourly data
+ ## start time is datestr(tuk_time(1))
+ ## Latitude of obs
+ ## Add a shallow-water constituent
+ ## coloured boostrap CI
+ [tidestruc, pout] = t_tide (tuk_elev, 'interval', 1, 'start', tuk_time (1), 'latitude', 69 + 27 / 60, 'inference', infername, inferfrom, infamp, infphase, 'shallow', 'M10', 'error', 'linear', 'synthesis', 1);
warning: /home/filipe/IOOS/notebooks_demos/notebooks/t_tide_v1.3beta/t_tide.m: possible Matlab-style short-circuit operator at line 443, column 18
warning: /home/filipe/IOOS/notebooks_demos/notebooks/t_tide_v1.3beta/t_tide.m: possible Matlab-style short-circuit operator at line 637, column 19
warning: load: file found in load path
number of standard constituents used: 35
Forced fit to M10
Inference of P1 using K1
Inference of K2 using S2
Points used: 1510 of 1584
percent of var residual after lsqfit/var original: 74.18 %
warning: /home/filipe/IOOS/notebooks_demos/notebooks/t_tide_v1.3beta/t_vuf.m: possible Matlab-style short-circuit operator at line 68, column 22
warning: load: file found in load path
Greenwich phase computed with nodal corrections applied to amplitude
and phase relative to center time
Do inference corrections
Using linearized error estimates
Generating prediction with nodal corrections, SNR is 1.000000
warning: /home/filipe/IOOS/notebooks_demos/notebooks/t_tide_v1.3beta/t_predic.m: possible Matlab-style short-circuit operator at line 66, column 34
warning: /home/filipe/IOOS/notebooks_demos/notebooks/t_tide_v1.3beta/t_predic.m: possible Matlab-style short-circuit operator at line 173, column 18
warning: isstr is obsolete and will be removed from a future version of Octave, please use ischar instead
warning: load: file found in load path
warning: load: file found in load path
percent of var residual after synthesis/var original: 78.42 %
-----------------------------------
date: 29-Mar-2017
nobs = 1584, ngood = 1510, record length (days) = 66.00
start time: 06-Jul-1975 01:00:00
rayleigh criterion = 1.0
Greenwich phase computed with nodal corrections applied to amplitude \n and phase relative to center time
x0= 1.98, x trend= 0
var(x)= 0.82196 var(xp)= 0.17966 var(xres)= 0.64461
percent var predicted/var original= 21.9 %
tidal amplitude and phase with 95% CI estimates
tide freq amp amp_err pha pha_err snr
MM 0.0015122 0.2121 0.521 263.34 140.72 0.17
MSF 0.0028219 0.1561 0.521 133.80 191.29 0.09
ALP1 0.0343966 0.0152 0.035 334.95 143.54 0.19
2Q1 0.0357064 0.0246 0.035 82.69 89.79 0.48
Q1 0.0372185 0.0158 0.035 65.74 140.51 0.2
*O1 0.0387307 0.0764 0.035 74.23 29.21 4.7
NO1 0.0402686 0.0290 0.035 238.14 53.29 0.67
*P1 0.0415526 0.0465 0.035 71.88 43.41 1.7
*K1 0.0417807 0.1405 0.035 64.81 15.24 16
J1 0.0432929 0.0253 0.035 7.32 86.65 0.51
*OO1 0.0448308 0.0531 0.035 235.75 43.75 2.3
UPS1 0.0463430 0.0298 0.035 91.73 87.12 0.71
EPS2 0.0761773 0.0211 0.025 184.59 66.90 0.7
*MU2 0.0776895 0.0419 0.025 83.23 33.79 2.8
*N2 0.0789992 0.0838 0.025 44.52 16.86 11
*M2 0.0805114 0.4904 0.025 77.70 2.89 3.8e+02
L2 0.0820236 0.0213 0.025 35.22 82.98 0.71
*S2 0.0833333 0.2197 0.025 126.72 6.58 76
*K2 0.0835615 0.0598 0.025 149.12 28.01 5.6
ETA2 0.0850736 0.0071 0.025 246.05 244.76 0.08
*MO3 0.1192421 0.0148 0.010 234.97 40.62 2.3
*M3 0.1207671 0.0123 0.010 261.57 44.22 1.6
MK3 0.1222921 0.0049 0.010 331.60 117.53 0.25
SK3 0.1251141 0.0023 0.010 237.69 252.59 0.057
*MN4 0.1595106 0.0092 0.009 256.47 52.74 1.1
*M4 0.1610228 0.0126 0.009 291.78 38.58 2
SN4 0.1623326 0.0083 0.009 270.85 59.58 0.89
MS4 0.1638447 0.0010 0.009 339.35 479.33 0.014
S4 0.1666667 0.0047 0.009 299.56 108.15 0.28
2MK5 0.2028035 0.0013 0.005 310.10 214.09 0.073
2SK5 0.2084474 0.0045 0.005 104.00 62.55 0.94
2MN6 0.2400221 0.0035 0.007 271.24 101.52 0.28
M6 0.2415342 0.0017 0.007 158.88 207.26 0.067
2MS6 0.2443561 0.0056 0.007 306.10 65.10 0.71
2SM6 0.2471781 0.0023 0.007 298.92 165.13 0.12
*3MK7 0.2833149 0.0086 0.004 212.25 29.47 3.7
M8 0.3220456 0.0030 0.003 42.43 56.78 0.86
M10 0.4025570 0.0009 0.003 198.23 195.47 0.07
+ ## Use SNR=1 for synthesis.
+ echo ('off')
warning: get: allowing linewi to match line property linewidth
error: get: ambiguous text property name vertical; possible matches:
verticalalignment verticalalignmentmode
error: called from:
error: /usr/share/octave/3.8.2/m/plot/appearance/text.m at line 152, column 17
error: /home/filipe/IOOS/notebooks_demos/notebooks/t_tide_v1.3beta/t_demo.m at line 57, column 1
