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(The color black could also be dedicated to identifying the lowest elevation in the design of the Color Contour plot, in which case, bothschemes would be equal in this regard.)

As we learned earlier, the lowest elevation occurs at four different points on the surface, and those points are near the corners.

The elevation of the valleys

Both plots show that while the valleys between the central and minor peaks are very deep, they aren't quite as deep as the lowest elevation. They are bluein the Color Shift plot and gray in the Color Contour plot. Because the gray color represents a somewhat smaller elevation range in the Color Contour plotthan the blue represents in the Color Shift plot, the elevation of the valley is defined more accurately in the Color Contour plot.

A logarithmic conversion

Sometimes when plotting data, it is useful to plot the logarithm of the data values instead of the raw values.

(For many years, engineers have plotted data on graph paper referred to either as semi-log paper or log-log paper. Each type of graph paper hasadvantages and disadvantages relative to the other type and also has advantages and disadvantages relative to linear graph paper. This programprovides a capability that is analogous to the use of semi-log paper but in a 3D sense.)

Flattens the plot

The use of semi-log paper has the effect of flattening the plot in the 2D case, or flattening the surface in the 3D case. The semi-log approach tends topull the structure of the low-level values up so that they can be better observed. The logarithm of the low elevations is closer to the maximum elevationthan is the raw value of the low elevations.

More sample output

The three images in the top row of Figure 2 are reproductions of the three images in Figure 1 . They were included in Figure 2 for comparison with the bottom three images in Figure 2 .

Figure 2 . Sample output with logarithmic flattening.
Missing Figure.

The bottom three images in Figure 2 were produced in exactly the same way as the top three images except that prior to creating the image the elevationvalues for the surface were converted to the log base 10 of the raw elevation values.

Six different formats

Thus, Figure 2 shows the same 3D surface plotted using six different plotting formats. Going from left to right and top to bottom, the six images illustrate:

  • Grayscale (linear)
  • Color Shift (linear)
  • Color Contour (linear)
  • Grayscale with logarithmic data flattening
  • Color Shift with logarithmic data flattening
  • Color Contour with logarithmic data flattening

Isolates the location of the minima

The significance of the logarithmic conversion can be seen by comparing the two images on the right side of Figure 2 . When the raw elevation values were quantized into 23 levels, quite a few of the elevation values were quantizedinto the minimum value as indicated by the black areas in the top image.

However, after converting the elevation values to logarithmic values, only four points quantized to the minimum value as indicated by the four small blacksquares in the bottom right image. Thus, the top image on the right shows the general area of the lowest elevations on the surface whereas the bottom image onthe right clearly identifies the exact location of each of the four lowest elevations.

Questions & Answers

what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Digital signal processing - dsp. OpenStax CNX. Jan 06, 2016 Download for free at https://legacy.cnx.org/content/col11642/1.38
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