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{{about||the notion of diameter in graph theory|Distance (graph theory)|the computer network protocol|Diameter (protocol)}}
April 17, 2013 - Creating a website from the ground-up can be both fun and challenging simultaneously. You are probably wondering simply how much designing your site will cost and where to find a designer. Read on to learn some principles of basic web design planning so that you can do things the proper way from the beginning.<br><br>Research the different resources accessible to you. There are a wide array of different magazines and books on the subject offering advice for newbies and experienced web site designers alike. This is a wonderful approach to learn all of the nuances of your craft while learning to be a good designer.<br><br>Site design and upkeep of that website, requires your very own office space. Clear away the area of distractions and make an environment where your can focus. Make certain your tools are within easy access, and that you have adequate space for the web design needs.<br><br>Buying books on web site design or [http://youtu.be/giHrwvqy3G0 just click here] is money wisely spent. Be sure you start out with information which is targeted to your existing design level; you need to improve your skills, however, you want to make sure you don't miss any information as you go.<br><br>Keep your early site building efforts small, to help you more easily identify what's working, and what's not. Create pages that encompass plain text to begin with, and build after that as you gain confidence.<br><br>It is important to create realistic goals about how exactly long each web site design tasks is going to take to complete. Working toward an unrealistic deadline may cause poor work, and will [http://www.Youtube.com/watch?v=ER69yWwD1F4 create larger] issues down the road. Make sure you have the time to work thoroughly and carefully.<br><br>If you are making a very big website, you want to always incorporate a search function to the site. This really is commonly located in the topmost-right corner with the screen being an empty bar, which users can insert looking term or phrase. FreeFind and Google both have these capabilities for any website.<br><br>Something web designers need to learn is to estimate just how long that common website design tasks is going to take. If you rush to meet an impossible deadline, you will not do your best work and may have to troubleshoot a web site later. It is preferable when you can allow yourself lots of time to do work with care.<br><br>Speed is king on the Internet, so that you need to make sure your internet pages load quickly. If Internet users have to wait a long time for your web site to load, they are going to probably leave your website before it loads and vow to never return.<br><br>Most visitors to your website will probably be annoyed by popups or links that just open in a new window. Many people will have pop-ups disabled at the browser level. They are techniques that needs to be avoided. In case you are thinking about utilizing these techniques for navigational purposes, you should instead consider whether the overall navigation system you've got in place for that website could use improvement.<br><br>Go through the previous work associated with a web design company you hire. You would like to make sure that they may be trusted, and that they offer the quality at work that you're looking for in a site. An internet designer's portfolio will let you know if their style is perfect for your site and when they produce quality website pages.<br><br>A great tip for anyone looking to get into website design is to use a number of the many resources out there. There are thousands of well-written publications available to help anyone find out more about web design principles and techniques. It's a good approach to learn more about website design and to get better at it.<br><br>Look at a domain auction like a source for prospective domains. Established sites, for example SEDO, will facilitate buying a domain name that already exists. It costs more than purchasing a new domain, but all the benefits make it worth every penny!<br><br>It may be necessary to enlist the aid of a professional site designer, or perhaps a close friend, that has some experience with the matter. Aligning yourself by having an expert will greatly accelerate your personal learning process.<br><br>While using the services of your website design company, it is best to make sure that you pay your bill promptly. These businesses work to sustain your website. Once you don't pay them, they're less likely to offer you help if something goes wrong on your website. Paying your bill promptly establishes rapport with all the company and can ensure that your concerns are addressed quickly.<br><br>Don't copy other websites' designs in your niche or make websites that are too much like your competitors' websites. Go review your competitors' websites. In case you are too similar visitors might confuse your internet site with the competition. Additionally, you will just be a generic sort of a similar site that came before yours.<br><br>If you wish to attract visitors to your website, you have to make the site user friendly and attractive. A web site that is well-designed encourages website visitors to stay, keep coming back and share, resulting in a big increase in traffic. However, websites which are unattractive and poorly designed can discourage prospective customers from returning in the future. Use the web site design strategies you merely learned to significantly increase the chance your website will succeed. co-edited by Whitley F. Warnock
{{distinguish|Demeter}}
 
[[File:Circle-withsegments.svg|thumb|200px|right|Circle illustration with [[circumference]] (C) in black, diameter (D) in cyan, radius (R) in red, and centre or origin (O) in magenta.]]
In [[geometry]], the '''diameter''' of a [[circle]] is any straight [[line segment]] that passes through the center of the circle and whose endpoints lie on the circle. It can be also defined as the longest [[chord (geometry)|chord]] of the circle. Both definitions are also valid for the diameter of a [[sphere]]. The word "diameter" is derived from [[Greek language|Greek]] ''διάμετρος'' (''diametros''), "diameter of a circle", from ''δια-'' (''dia-''), "across, through" + ''μέτρον'' (''metron''), "measure".<ref>[http://www.etymonline.com/index.php?term=diameter Online Etymology Dictionary]</ref> It is often abbreviated '''DIA''', '''dia''', '''d''', or '''[[#Diameter symbol|⌀]]'''.
 
In more modern usage, the length of a diameter is also called the diameter. In this sense one speaks of ''the'' diameter rather than ''a'' diameter (which refers to the line itself), because all diameters of a circle or sphere have the same length, this being twice the [[radius]] '''r'''.
 
: <math>d = 2r \quad \Rightarrow \quad r = \frac{d}{2}.</math>
 
For a [[convex set|convex shape]] in the plane, the diameter is defined to be the largest distance that can be formed between two opposite [[parallel lines]] tangent to its boundary, and the ''width'' is defined to be the smallest such distance. Both quantities can be calculated efficiently using [[rotating calipers]].<ref>{{cite journal
| author = Toussaint, Godfried T.
| title = Solving geometric problems with the rotating calipers
| publisher=Proc. MELECON '83, Athens
|url=http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.155.5671
|year = 1983
}}</ref> For a [[curve of constant width]] such as the [[Reuleaux triangle]], the width and diameter are the same because all such pairs of parallel tangent lines have the same distance. See also [[Tangent lines to circles]].
 
==Generalizations==
The definitions given above are only valid for circles, spheres and convex shapes. However, they are special cases of a more general definition that is valid for any kind of ''n''-dimensional convex or non-convex object, such as a [[hypercube]] or a set of scattered points. The '''diameter''' of a [[subset]] of a [[metric space]] is the [[supremum|least upper bound]] of the set of all distances between pairs of points in the subset. So, if ''A'' is the subset, the diameter is
:[[supremum|sup]] { d(''x'', ''y'') | ''x'', ''y'' ∈ ''A'' } .
If the [[distance function]] d is viewed here as having [[codomain]] '''R''' (the set of all [[real number]]s), this implies that the diameter of the [[empty set]] (the case {{nowrap|1=''A'' = ∅}}) equals −∞ ([[negative infinity]]). Some authors prefer to treat the empty set as a special case, assigning it a diameter equal to 0,<ref>[http://at.yorku.ca/cgi-bin/bbqa?forum=ask_a_topologist_2004;task=show_msg;msg=0860.0002 Re: diameter of an empty set]</ref> which corresponds to taking the codomain of d to be the set of nonnegative reals.
 
For any solid object or set of scattered points in n-dimensional [[Euclidean space]], the diameter of the object or set is the same as the diameter of its [[convex hull]].  
 
In [[differential geometry]], the diameter is an important global [[Riemannian geometry|Riemannian]] [[invariant (mathematics)|invariant]].  
 
In plane geometry, a diameter of a [[conic section]] is typically defined as any chord which passes through the conic's centre; such diameters are not necessarily of uniform length, except in the case of the circle, which has [[eccentricity (mathematics)|eccentricity]]&nbsp;''e''&nbsp;=&nbsp;0.
 
In medical [[Idiom#Parlance|parlance]] the diameter of a [[lesion]] is the longest line segment whose endpoints are within the lesion.
 
==Diameter symbol==
[[Image:Technical Drawing Hole 01.png|thumb|122px|Sign {{Unicode|⌀}} in a technical drawing]]
[[Image:Sign diameter.png|thumb|150px|Sign {{Unicode|⌀}} from [[AutoCAD]] drawing]]
{{distinguish2|the Scandinavian letter "[[Ø]]" or the [[Empty set]] symbol {{italics correction|"}}''{{Unicode|∅}}''"}}
 
The [[symbol]] or [[variable (mathematics)|variable]] for diameter, {{Unicode|⌀}}, is [[Homoglyph|similar in size and design]] to [[ø]], the Latin small letter o with stroke. [[Unicode]] provides character number 8960 ([[hexadecimal]] 2300) for the symbol, which can be encoded in [[HTML]] webpages as <tt>&amp;#8960;</tt> or <tt>&amp;#x2300;</tt>. The character can be obtained in [[Microsoft Windows]] by holding the {{key press|[[Alt key|Alt]]}} key down while entering {{key press|8}}{{key press|9}}{{key press|6}}{{key press|0}} on the [[numeric keypad]]. On an [[Apple, Inc.|Apple]] [[Macintosh]], the diameter symbol can be entered via the character palette (this is opened by pressing {{key press|Opt}}{{key press|Cmd}}{{key press|T}} in most applications), where it can be found in the Technical Symbols category.
 
The character will sometimes not display correctly, however, since many [[Typeface|font]]s do not include it. In most situations the letter ø is acceptable, which is unicode 0248 (hexadecimal 00F8). It can be obtained in UNIX-like operating systems using a [[Compose key]] by pressing, in sequence, {{key press|[[Compose key|Compose]]}}{{key press|/}}{{key press|o}} and on a Macintosh by pressing {{key press|Opt}} {{key press|O}} (in both cases, that is the letter [[o]], not the number [[0 (number)|0]]).
 
In [[LaTeX]] the symbol is achieved with the command \diameter which is part of the wasysym package.
 
The diameter symbol {{Unicode|&#x2300;}} is distinct from the [[empty set]] symbol {{Unicode|∅}}, from an ([[italic script|italic]]) uppercase [[Phi (letter)|phi]] ''Φ'', and from the Nordic vowel [[Ø]].<ref>{{citation|title=Unicode Explained|first=Jukka K.|last=Korpela|publisher=O'Reilly Media, Inc.|year=2006|isbn=978-0-596-10121-3|pages=23–24|url=http://books.google.com/books?id=lxndiWaFMvMC&pg=PA23}}.</ref>
 
==See also==
* [[Angular diameter]]
* [[Caliper]], [[micrometer]], tools for measuring diameters
* [[Eratosthenes]], who calculated the diameter of the [[Earth]] around 240 BC.
* [[Distance (graph theory)|Graph or network diameter]]
* [[Hydraulic diameter]]
* [[List_of_gear_nomenclature#Inside diameter|Inside diameter]]
* [[Jung's theorem]], an inequality relating the diameter to the radius of the [[circumradius|smallest enclosing ball]]
* [[Sauter mean diameter]]
 
==Notes==
{{reflist}}
 
[[Category:Elementary geometry]]
[[Category:Length]]
[[Category:Circles]]

Revision as of 00:43, 4 March 2014

April 17, 2013 - Creating a website from the ground-up can be both fun and challenging simultaneously. You are probably wondering simply how much designing your site will cost and where to find a designer. Read on to learn some principles of basic web design planning so that you can do things the proper way from the beginning.

Research the different resources accessible to you. There are a wide array of different magazines and books on the subject offering advice for newbies and experienced web site designers alike. This is a wonderful approach to learn all of the nuances of your craft while learning to be a good designer.

Site design and upkeep of that website, requires your very own office space. Clear away the area of distractions and make an environment where your can focus. Make certain your tools are within easy access, and that you have adequate space for the web design needs.

Buying books on web site design or just click here is money wisely spent. Be sure you start out with information which is targeted to your existing design level; you need to improve your skills, however, you want to make sure you don't miss any information as you go.

Keep your early site building efforts small, to help you more easily identify what's working, and what's not. Create pages that encompass plain text to begin with, and build after that as you gain confidence.

It is important to create realistic goals about how exactly long each web site design tasks is going to take to complete. Working toward an unrealistic deadline may cause poor work, and will create larger issues down the road. Make sure you have the time to work thoroughly and carefully.

If you are making a very big website, you want to always incorporate a search function to the site. This really is commonly located in the topmost-right corner with the screen being an empty bar, which users can insert looking term or phrase. FreeFind and Google both have these capabilities for any website.

Something web designers need to learn is to estimate just how long that common website design tasks is going to take. If you rush to meet an impossible deadline, you will not do your best work and may have to troubleshoot a web site later. It is preferable when you can allow yourself lots of time to do work with care.

Speed is king on the Internet, so that you need to make sure your internet pages load quickly. If Internet users have to wait a long time for your web site to load, they are going to probably leave your website before it loads and vow to never return.

Most visitors to your website will probably be annoyed by popups or links that just open in a new window. Many people will have pop-ups disabled at the browser level. They are techniques that needs to be avoided. In case you are thinking about utilizing these techniques for navigational purposes, you should instead consider whether the overall navigation system you've got in place for that website could use improvement.

Go through the previous work associated with a web design company you hire. You would like to make sure that they may be trusted, and that they offer the quality at work that you're looking for in a site. An internet designer's portfolio will let you know if their style is perfect for your site and when they produce quality website pages.

A great tip for anyone looking to get into website design is to use a number of the many resources out there. There are thousands of well-written publications available to help anyone find out more about web design principles and techniques. It's a good approach to learn more about website design and to get better at it.

Look at a domain auction like a source for prospective domains. Established sites, for example SEDO, will facilitate buying a domain name that already exists. It costs more than purchasing a new domain, but all the benefits make it worth every penny!

It may be necessary to enlist the aid of a professional site designer, or perhaps a close friend, that has some experience with the matter. Aligning yourself by having an expert will greatly accelerate your personal learning process.

While using the services of your website design company, it is best to make sure that you pay your bill promptly. These businesses work to sustain your website. Once you don't pay them, they're less likely to offer you help if something goes wrong on your website. Paying your bill promptly establishes rapport with all the company and can ensure that your concerns are addressed quickly.

Don't copy other websites' designs in your niche or make websites that are too much like your competitors' websites. Go review your competitors' websites. In case you are too similar visitors might confuse your internet site with the competition. Additionally, you will just be a generic sort of a similar site that came before yours.

If you wish to attract visitors to your website, you have to make the site user friendly and attractive. A web site that is well-designed encourages website visitors to stay, keep coming back and share, resulting in a big increase in traffic. However, websites which are unattractive and poorly designed can discourage prospective customers from returning in the future. Use the web site design strategies you merely learned to significantly increase the chance your website will succeed. co-edited by Whitley F. Warnock

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