1. Delphi Static Class
2. Delphi Constant String Array

DelPhi is a scientific application which calculates electrostatic potentials in and around macromolecules and the corresponding electrostatic energies. It incorporates the effects of ionic strength mediated screening by evaluating the Poisson-Boltzmann equation at a finite number of points within a three-dimensional grid box. DelPhi is commonly used in protein science to visualize variations in electrostatics along a protein or other macromolecular surface and to calculate the electrostatic components of various energies.^[1]

Development[edit]

The Const keyword is used to start a section of constant definitions. The section is terminated by the next keyword in a program. Within the section, one or more constants may be defined. These can be a mixture of normal or typed constants: 1.Normal constants. These give a name Name1 to a fixed expression, Expression1. Delphi creates separate runtime type information for that type, and treats the new. Unlike standard Pascal, Delphi lets you declare the type of a constant,. Delphi Parameters (var, const) Mike Prestwood is a drummer, an author, and creator of the PrestwoodBoards online community. He is the President & CEO of Prestwood IT Solutions.Prestwood IT provides Coding, Website, and Computer Tech services.

One of the main problems in modeling the electrostatic potential of biological macromolecules is that they exist in water at a given ionic strength and that they have an irregular shape. Analytical solutions of the corresponding Poisson-Boltzmann Equation (PBE) are not available for such cases and the distribution of the potential can be found only numerically. DelPhi, developed in Professor Barry Honig's lab in 1986, was the first PBE solver used by many researchers. The widespread popularity of DelPhi is due to its speed, accuracy (calculation of the electrostatic free energy is only slightly dependent on the resolution of the grid) and the ability to handle extremely high grid dimensions.

Features[edit]

Additional features such as assigning different dielectric constants to different regions of space, smooth Gaussian-based dielectric distribution function,^[2] modeling geometric objects and charge distributions, and treating systems containing mixed salt solutions also attracted many researchers. In addition to the typical potential map, DelPhi can generate and output the calculated distribution of either the dielectric constant or ion concentration, providing the biomedical community with extra tools for their research.^[3][4][5]

Pdb files are typically used as input for DelPhi calculations. Other required inputs are an atomic radii file and a charge file.^[6] Binary Potential files as output from DelPhi can be viewed in most molecular viewers such as UCSF Chimera, Jmol, and VMD, and can either be mapped onto surfaces or visualized at a fixed cutoff.^[7]

Delphi Static Class

Versions[edit]

Delphi distribution comes as a sequential as well as parallelized codes, runs on Linux, Mac OS X and Microsoft Windows systems and the source code is available in Fortran 95 and C++ programming languages. DELPHI is also implemented into an accessible web-server.^[8] DELPHI has also been utilized to build a server that predicts pKa's of biological macromolecules such as proteins, RNAs and DNAs which can be accessed via web.^[9]

DelPhi v.7 is distributed in four versions:

Delphi Constant String Array

1. IRIX version, compiled under IRIX 6.5 Operating System, 32bits, using f77 and cc compilers.
2. IRIX version, compiled under IRIX 6.5 Operating System, 64bits, using f77 and cc compilers.
3. LINUX version, compiled under Red Hat 7.1, kernel 2.4.2 Operating System, using GNU gfortran compilers,
4. PC version, compiled under Windows Operating System, using Microsoft Developer Studio C++ and Fortran compilers.

Their way of working is very similar; however, unexpected differences may appear due to different numerical precision or to the porting of the software to different architectures. For example, the elapsed time in the PC version is not calculated at present.

Cara convert jpg ke pdf. Each distribution contains one executable (named delphi or delphi.exe), the source codes (with corresponding makefile when needed), and some worked examples.

See also[edit]

External links[edit]

References[edit]

1. ^Rohs R, West SM, Sosinsky A, Liu P, Mann RS, Honig B (October 2009). 'The role of DNA shape in protein-DNA recognition'. Nature. 461 (7268): 1248–53. doi:10.1038/nature08473. PMC2793086. PMID19865164.
2. ^Li L, Li C, Zhang Z, Alexov E (2013). 'On the Dielectric 'Constant' of Proteins: Smooth Dielectric Function for Macromolecular Modeling and Its Implementation in DelPhi'. Journal of Chemical Theory and Computation. 9 (4): 2126–2136. doi:10.1021/ct400065j. PMC3622359. PMID23585741.
3. ^'Software:DelPhi'. Honig Lab. Columbia University.
4. ^Rocchia W, Sridharan S, Nicholls A, Alexov E, Chiabrera A, Honig B (2002). 'Rapid grid-based construction of the molecular surface and the use of induced surface charge to calculate reaction field energies: applications to the molecular systems and geometric objects'. Journal of Computational Chemistry. 23 (1): 128–37. doi:10.1002/jcc.1161. PMID11913378.
5. ^Li L, Li C, Sarkar S, Zhang J, Witham S, Zhang Z, Wang L, Smith N, Petukh M, Alexov E (2012). 'DelPhi: a comprehensive suite for DelPhi software and associated resources'. BMC Biophysics. 5: 9. doi:10.1186/2046-1682-5-9. PMC3463482. PMID22583952.
6. ^'DelPhi Parameter Files'.
7. ^DelPhi manual
8. ^'DelPhi Webserver'.
9. ^'DelPhiPka Webserver'.

When Delphi invokes an event handler, the old values of local variables are wiped out. What if we want to keep track of how many times a button has been clicked? We could have the values persist by using a unit-level variable, but it is generally a good idea to reserve unit-level variables only for sharing information. Fairy tail last season. What we need are usually called static variables or typed constants in Delphi.

Variable or Constant

Typed constants can be compared to initialized variables-variables whose values are defined on entry to their block (usually event handler). Such a variable is initialized only when the program starts running. After that, the value of a typed constant persists between successive calls to their procedures.

Using typed constants is a very clean way of implementing automatically initialized variables. To implement these variables without typed constants, we'll need to create an initialization section that sets the value of each initialized variable.

Variable Typed Constants

Although we declare typed constants in the const section of a procedure, it is important to remember that they are not constants. At any point in your application, if you have access to the identifier for a typed constant you'll be able to modify its value.

To see typed constants at work, put a button on a blank form, and assign the following code to the OnClick event handler:

Notice that every time you click on the button, forms caption increments steadily.
Now try the following code:

We are now using an uninitialized variable for the clicks counter. Notice that weird value in the forms caption after you click on the button.

Constant Typed Constants

You have to agree that idea of modifiable constants sounds a bit strange. In 32 bit versions of Delphi Borland decided to discourage their use, but support them for Delphi 1 legacy code.

We can enable or disable Assignable typed constants on the Compiler page of the Project Options dialog box.

If you've disabled Assignable typed constants for a given project, when you attempt to compile previous code Delphi will give you 'Left side cannot be assigned to' error upon compilation. You can, however, create assignable typed constant by declaring:

Therefore, the first example code looks like:

Conclusion

It's up to you to decide whether you want typed constants to be assignable or not. The important thing here is that besides ideal for counters, typed constants are ideal for making components alternately visible or invisible, or we can use them for switching between any Boolean properties. Typed constants can also be used inside TTimer's event handler to keep track of how many times even has been triggered.