N for glasspdf

Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .

Refraction is the change in direction of a wave due to a change in speed at the boundary between two media of different density. The Latin word "fract" in refraction means to break. Refraction is the "breaking or bending" of waves as it travels to a different density media. The absolute index of refraction of a material is defined as the ratio of the speed of light in a vacuum (c) with respect to the speed of light in the material (v). From this definition, we see that the index of refraction is a dimensionless number that is greater than one because c is always greater than v.

N for glassuses

As you cannot push the poles beyond a point without affecting filter stability, in order to improve the brickwall approximation of the filter, you must increase the filter order. Use the FilterOrder design parameter to set the notch or peak filter order, and the SystemObject=true option to design a dsp.SOSFilter System object. Compare a second order notch filter design against a sixth order notch filter.

N for glassrefraction

Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.

N glassPhysics

You can implement a tunable peak filter similarly using the dsp.NotchPeakFilter object or by using the iirpeak function and dsp.SOSFilter object.

Peak filters are used to retain only a single frequency component (or a small band of frequencies) from a signal. Use the same designNotchPeakIIR function to compute the coefficients of a peak filter.

The index of refraction varies with frequency or color. Frequency does not change as light travels from one medium to another. Since frequency remains unchanged, the change in the speed of light in the material is directly proportional to the change in the wavelength of light as it travels from one medium to another.

The name crown glass comes from the manufacturing process. But, it actually is a type soda-lime glass, which is one of the most common glass made on earth. Crown glass that were made into windows were made by blowing glass into a hollow tube. As the tube and the flat disk is spun, it spins out a crown shaped piece of glass where it forms at the bottom of the hollow tube. Crown glass is also used for optical glasses that are used in compound lenses. It has a lower refractive index and less dispersion than flint glass, but is more durable. Based of the research, crown glass has a refractive index in the range of 1.5 to 1.6.

For a given filter order, you can obtain sharper transitions by allowing for passband or stopband ripples or both. This can be accomplished by using the fdesign.notch and the fdesign.peak filter specification objects. All specifications and tradeoffs mentioned so far apply equally to notch and peak filters.

N for glasstest

Using time-varying filters requires changing the coefficients of the filter while the simulation runs. This is achieved by calling the designNotchPeakIIR function during runtime with the changing parameters. Alternatively, the DSP System Toolbox™ provides the dsp.NotchPeakFilter object to design and implement time-varying (tunable) second-order notch and peak filters.

Design another second-order filter by specifying the quality factor and using it to calculate the 3-dB bandwidth. Use the designNotchPeakIIR function to compute the filter coefficients. Visualize the magnitude response of the filter.

N for glassmeaning

You can also design the filter by specifying the quality factor. Quality factor is defined as the ratio of the notch or peak frequency F0 and the bandwidth BW: Q=F0/BW. The quality factor is a measure of how well you can isolate the desired frequency from the other frequencies. When you fix the filter order, you can achieve a higher Q by pushing the poles closer to the zeros. However, specifying the bandwidth is a more convenient way of achieving exactly the desired shape for the designed filter.

N for glassformula

In order to implement a time-varying filter, create a dynamic setup to simulate the filter and implement the filter with time-varying design parameters.

This example shows how to design peak and notch filters. Filters that peak or notch at a certain frequency retain or eliminate a particular frequency component of a signal. The design parameters that you can set for such filters are the frequency at which you want the peak or notch and the 3-dB bandwidth or the Q factor. Using these specifications and by increasing the filter order, you can design filters that more closely approximate an ideal filter.

Start by creating a dynamic streamed simulation with filters whose coefficients do not change. Create two second-order notch filters, the first using the dsp.SOSFilter object and the second using the dsp.NotchFilter object. In the first filter, set the center frequency to 1 kHz, and the bandwidth at –3 dB to 500 Hz. Calculate the coefficients of this filter directly using the designNotchPeakIIR function. In the second filter, set the center frequency to 3 kHz and the bandwidth at –3 dB to 500 Hz. The sample rate for both filters is 8 kHz. Use the Verbose=true option to print the default values of unspecified parameters. In this case, FilterOrder is not specified and defaults to 2.

The coefficients of time-varying filters change over time due to runtime changes in the design parameters (for example, the center frequency for a notch filter). Create two second-order notch filters with time-varying design parameters. As with the static filter, use the designNotchPeakIIR function and the dsp.SOSFilter object to implement the first filter, and the dsp.NotchPeakFilter object to implement the second filter. Vary the design parameters of both filters over time.

Suppose that you want to eliminate a 60 Hz interference in a signal sampled at 3000 Hz. You can use a second-order notch filter in this case and use the designNotchPeakIIR function to compute the coefficients of the filter. The function expects frequencies in normalized units. Scale the design parameters accordingly and specify them to the function. Use the Response="notch" option to design a notch filter and Response="peak" option to design a peak filter.