GNU Octave Matlab: Plot tick labeling - matlab

Question

I am making a frequency plot and I would like some help on tick labeling.
Here is what I have:
semilogx([200,1000,5000], [0,6,0]);
xlim([20 20000]);
sc = [20:10:100,125:25:175];
scale = [sc,sc*10,sc*100, 20000];
xticks(scale);
xticklabels(scale);
set(gca,'XMinorTick','Off')
grid on;
set (gca, "xminorgrid", "off")
xlabel('frequency (Hz)');
ylabel('dB');
How can I make all numbers from 1000 and upwards appear as 1K, 2K, 5K and so on?
How could I make the lines on 50,100,200,500,1K,2K,5K,10K appear thicker/more black?

Answer 1

Octave approach (probably works on matlab too though)
I wouldn't rely on latex trickery to do this to be honest.
Here is the way I usually do stuff like this.
Effectively, because the axis labels object is considered a single object, and you cannot split it into parts, the trick is to overlay an invisible, bare-minimum axes object defining only the labels you want, and treat those as you'd like (e.g. adjust its fontweight, fontsize, xcolor, etc etc).
H = semilogx([200,1000,5000], [0,6,0]);
A = gca();
B = axes();
subscale = [20:10:100,125:25:175];
scale = [subscale,subscale * 10,subscale * 100, 20000];
ScaleTextLabels = {};
for i = 1 : length( scale )
if scale(i) >= 1000, ScaleTextLabels{i} = sprintf("%dk", scale(i) / 1000 );
else, ScaleTextLabels{i} = num2str( scale(i) );
end
end
SpecialTickLabels = { '50', '100', '200', '500', '1k', '2k', '5k', '10k'};
ScaleIndices = 1 : length( ScaleTextLabels );
SpecialIndices = nthargout( 2, #ismember, SpecialTickLabels, ScaleTextLabels );
NormalIndices = setdiff( ScaleIndices, SpecialIndices );
set( A, 'xgrid', 'on', 'xlabel', 'frequency (Hz)', 'xlim', [20 20000] , 'xminorgrid', 'off', 'xminortick', 'off', 'xticklabel', ScaleTextLabels(NormalIndices), 'xtick', scale(NormalIndices) , 'ylabel', 'dB', 'gridlinestyle', ':', 'gridcolor', 'k', 'gridalpha', 0.5 );
set( B, 'xgrid', 'on', 'xlabel', '' , 'xlim', get( A, 'xlim' ), 'xminorgrid', 'off', 'xminortick', 'off', 'xticklabel', ScaleTextLabels(SpecialIndices), 'xtick', scale(SpecialIndices), 'ylabel', '' , 'color', 'none', 'fontsize', 12, 'fontweight', 'bold', 'position', get( A, 'position'), 'xcolor', [0,0,0], 'xscale', 'log', 'ylim', get( A, 'ylim'), 'ytick', [], 'gridlinestyle', '--', 'gridcolor', 'k', 'gridalpha', 0.8 );
This "layers of transparent axes objects" technique is very useful to keep in mind in general, it allows great flexibility when designing complex graphs. :)

Answer 2

In MATLAB
*I unfortunately could not yet find how to bold the specific lines
Adding the following code allows the ticks to converted to the new names/format suggested in part 1. For part 2 the best I could find out right now is bolding the specific numbers, unfortunately not the specific ticks/lines. Here \bf indicates which labels are to be bolded. All the names will correspond to the positions set originally by your axis vector scale. The last line in the code below indicates the replacement of the current axis, gca.
semilogx([200,1000,5000],[0,6,0]);
sc = [20:10:100,125:25:175];
scale = [sc,sc*10,sc*100, 20000];
Current_Axis = gca;
Current_Axis.XMinorTick = 'off';
xlabel('frequency (Hz)'); ylabel('dB');
xlim([20 20000]);
grid on;
X_Scale_Names = {'\bf20'; '30'; '40'; '\bf50'; '60';
'70';'80';'90';'\bf100';'125';'150';'175';'\bf200';'300';'400';
'500';'600';'700';'800';'900';'\bf1K';'1.25K';'1.5K';'1.75K';
'\bf2K';'3K';'4K';'\bf5K';'6K';'7K';'8K';'9K';'\bf10K';'12.5K';'15K';
'17.5K';'20K'};
To Adjust More Grid and Axis Properties:
Current_Axis = gca;
set(Current_Axis,'xtick',scale,'xticklabel',X_Scale_Names);
Current_Axis.LineWidth = 1;
Current_Axis.GridColor = 'k';
Current_Axis.GridAlpha = 0.5;
Ran using MATLAB R2019b

Answer 3

I did it like this:
semilogx([200,1000,5000], [0,6,0]);
xlim([20 20000]);
sc = [20:5:35,40:10:100,125:25:175];
scale = [sc,sc*10,sc*100, 20000];
xticks(scale);
xticklabels(scale);
set(gca,'XMinorTick','Off')
grid on;
set(gca,'gridlinestyle',':');
set(gca,'gridalpha',0.6);
set (gca, "xminorgrid", "off");
xg = [50,100,200,500,1000,2000,5000,10000]; #highlight grids
xx = reshape([xg;xg;NaN(1,length(xg))],1,length(xg)*3);
yy = repmat([ylim() NaN],1,length(xg));
line(xx,yy,'Color',[0.65,0.65,0.65]);
xlabel('frequency (Hz)');
ylabel('dB');
X_Scale_Names = {'\fontsize{11}\bf20'; '25'; '30';'35';'40'; '\fontsize{11}\bf50'; '60';
'70';'80';'90';'\fontsize{11}\bf100';'125';'150';'175';'\fontsize{11}\bf200';'250';'300';'350';'400';
'\fontsize{11}\bf500';'600';'700';'800';'900';'\fontsize{11}\bf1K';'1.25K';'1.5K';'1.75K';
'\fontsize{11}\bf2K';'2.5K';'3K';'3.5K';'4K';'\fontsize{11}\bf5K';'6K';'7K';'8K';'9K';'\fontsize{11}\bf10K';'12.5K';'15K';
'17.5K';'\fontsize{11}\bf20K'};
set(gca,'xtick',scale,'xticklabel',X_Scale_Names);
But I don't think this is the best/fastest/easiest way to do it...